Release v0.3.0: move settings into an on-demand single-instance configurator

CMakeLists.txt

@@ -1,36 +1,48 @@
 cmake_minimum_required(VERSION 3.24)
-project(KSwitcher VERSION 0.1.0 LANGUAGES CXX RC)
+project(KSwitcher VERSION 0.3.0 LANGUAGES CXX RC)
 if(NOT WIN32)
   message(FATAL_ERROR "KSwitcher uses native Windows APIs")
 endif()
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
-add_library(kscore src/core.cpp src/platform.cpp src/autostart.cpp src/autocorrect.cpp src/storage.cpp src/ocr.cpp src/richtext.cpp)
+add_library(kscore src/core.cpp src/platform.cpp src/autostart.cpp src/autocorrect.cpp src/storage.cpp src/ocr.cpp src/richtext.cpp src/update.cpp)
 target_include_directories(kscore PUBLIC src PRIVATE vendor)
 target_compile_definitions(kscore PUBLIC UNICODE _UNICODE WIN32_LEAN_AND_MEAN NOMINMAX _WIN32_WINNT=0x0A00)
 target_link_libraries(kscore PUBLIC user32 shell32 advapi32 crypt32 imm32 comctl32 gdi32 ole32 oleaut32 taskschd comdlg32 uuid windowscodecs runtimeobject uiautomationcore)
-add_executable(KSwitcher WIN32 src/main.cpp src/app.cpp src/ui.cpp resources/app.rc)
+add_executable(KSwitcher WIN32 src/main.cpp src/app.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
+target_compile_definitions(KSwitcher PRIVATE KS_RESIDENT_APP)
 target_link_libraries(KSwitcher PRIVATE kscore)
+add_executable(KSwitcherConfig WIN32 src/config_main.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
+set_target_properties(KSwitcherConfig PROPERTIES OUTPUT_NAME "KSwitcher.Config")
+target_compile_definitions(KSwitcherConfig PRIVATE KS_CONFIG_APP)
+target_link_libraries(KSwitcherConfig PRIVATE kscore)
 add_executable(KSwitcherTests tests/tests.cpp)
 target_link_libraries(KSwitcherTests PRIVATE kscore)
-add_executable(KSwitcherIntegration tests/integration.cpp src/app.cpp src/ui.cpp resources/app.rc)
+add_executable(KSwitcherIntegration tests/integration.cpp src/app.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
 target_link_libraries(KSwitcherIntegration PRIVATE kscore)
+add_executable(KSwitcherInputTests tests/input.cpp src/app.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
+target_link_libraries(KSwitcherInputTests PRIVATE kscore)
 add_executable(KSwitcherOcrTests tests/ocr.cpp)
 target_link_libraries(KSwitcherOcrTests PRIVATE kscore)
 if(MSVC)
-  set_property(TARGET kscore KSwitcher KSwitcherTests KSwitcherIntegration KSwitcherOcrTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+  set_property(TARGET kscore KSwitcher KSwitcherConfig KSwitcherTests KSwitcherIntegration KSwitcherInputTests KSwitcherOcrTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
   target_compile_options(kscore PRIVATE /W4 /utf-8)
   target_compile_options(KSwitcher PRIVATE /W4 /utf-8)
+  target_compile_options(KSwitcherConfig PRIVATE /W4 /utf-8)
 else()
   target_link_options(KSwitcher PRIVATE -municode -static -static-libgcc -static-libstdc++)
+  target_link_options(KSwitcherConfig PRIVATE -municode -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherTests PRIVATE -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherIntegration PRIVATE -static -static-libgcc -static-libstdc++)
+  target_link_options(KSwitcherInputTests PRIVATE -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherOcrTests PRIVATE -static -static-libgcc -static-libstdc++)
 endif()
 enable_testing()
 add_test(NAME native-regressions COMMAND KSwitcherTests)
+add_test(NAME input-regressions COMMAND KSwitcherInputTests)
+add_test(NAME updater-regressions COMMAND powershell.exe -NoProfile -ExecutionPolicy Bypass -File "${CMAKE_CURRENT_SOURCE_DIR}/tests/update.ps1" -Executable "$<TARGET_FILE:KSwitcher>")
 set_tests_properties(native-regressions PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
-install(TARGETS KSwitcher RUNTIME DESTINATION .)
+install(TARGETS KSwitcher KSwitcherConfig RUNTIME DESTINATION .)
 install(FILES LICENSE vendor/json-LICENSE.txt DESTINATION .)
 
 add_custom_command(TARGET KSwitcher POST_BUILD COMMAND ${CMAKE_COMMAND} -E copy_directory "${CMAKE_CURRENT_SOURCE_DIR}/dictionaries" "$<TARGET_FILE_DIR:KSwitcher>/dictionaries")

README.md

@@ -1,8 +1,10 @@
 # KSwitcher
 
-Native C++20 / Win32 rewrite of the Windows functionality of Typlo. Windows 10/11 x64.
+Native C++20 / Win32 rewrite of the Windows functionality of [Typlo](https://github.com/bitcodepro/Typlo). Windows 10/11 x64.
 No .NET, Avalonia, WebView, Qt, external graphics engine, or separately installed C++ runtime.
-The original Typlo project and its data remain separate.
+The original [Typlo](https://github.com/bitcodepro/Typlo) project and its data remain separate.
+
+**[User guide / Wiki](https://gitea.hrynco.com/hrynco/hrynco-kswitcher/wiki)** — setup, features, shortcuts, dictionaries, screenshots and troubleshooting (Ukrainian).
 
 ## Run
 
@@ -10,6 +12,16 @@ Run `build/KSwitcher.exe`, or extract `dist/KSwitcher-win-x64.zip` and run the e
 The build also refreshes the release copy in `build/release/`. Exit KSwitcher before rebuilding.
 The application lives in the notification area. Right-click its icon for Settings, Snippets and history.
 Double-click the tray icon to open Settings, the bold default menu item.
+Settings and the snippet editor run on demand in **KSwitcher.Config.exe**, beside the main executable.
+Repeated launches activate the existing configurator; closing its last window exits that process.
+Saving applies changes immediately through the resident KSwitcher process. The configurator does not
+load clipboard history, dictionaries or global input hooks. Clipboard history and the log viewer remain
+in the resident app. Keep both executables together when copying or updating the application.
+If settings change in the tray while the configurator is open, a conflicting Save is rejected; reopen
+the configurator to load the latest settings.
+The first upgrade from v0.2.3 or earlier to this two-executable build requires manual extraction:
+the older updater rejects additional executable files. Exit KSwitcher, replace both executables,
+and retain `data/` and customized dictionaries. Subsequent updates support both executables.
 In Settings, enable **Start with Windows** and **Start with Windows as administrator**
 to use a per-user Task Scheduler logon task with highest privileges. Enabling or changing
 the elevated task requests UAC approval if the app is not already elevated. No password is stored;
@@ -17,7 +29,7 @@ the task runs in the signed-in user's interactive session, including on battery
 Disabling the administrator option restores ordinary per-user startup; disabling startup stops
 future automatic launches. Saving unrelated settings does not recreate startup entries.
 `KSwitcher.exe --settings` opens Settings, including when the app is already running.
-Exit Typlo when using overlapping shortcuts to avoid competing keyboard hooks.
+Exit [Typlo](https://github.com/bitcodepro/Typlo) when using overlapping shortcuts to avoid competing keyboard hooks.
 
 ### Change a shortcut
 
@@ -34,6 +46,36 @@ combinations are intercepted. Unassigned shortcuts and simulated copy/paste pass
 Choose another shortcut or exit KSwitcher to restore the original action. Windows protects
 Ctrl+Alt+Delete and Win+L; these cannot be assigned.
 
+Keyboard and mouse input forwarded by Microsoft Mouse Without Borders follows the same input
+path as a local keyboard/mouse, including shortcuts, recent-word conversion and snippets.
+KSwitcher marks its own generated input so copy/paste, selection, modifier releases and shell-mask
+keys cannot trigger recursive commands or overwrite the recorded typing run. Other injected input
+is accepted, including key-up events and VK-only keyboard events. Unicode packets do not provide
+physical key positions and therefore reset recent-word tracking; selection conversion still works.
+
+### Updates
+
+Select **Update** in the tray menu to check the stable Releases of
+[this repository](https://gitea.hrynco.com/hrynco/hrynco-kswitcher/releases).
+A startup check also reports an available version, but never installs it automatically.
+Confirm the offered version to download and install it. The updater uses the existing
+`KSwitcher-win-x64.zip` and `SHA256SUMS.txt` assets, checks the checksum, package contents, x64
+executable identity and version, then closes and restarts KSwitcher. Downloads and staging happen
+before the application exits. If replacement or startup fails, it restores the previous files;
+if recovery itself fails, it reports the retained backup directory.
+
+Saved settings and clipboard history in `data/` or the local-app-data fallback are preserved.
+Existing dictionary files are preserved too; missing dictionary files are installed. Save settings
+edits before updating. The installation directory must be writable at KSwitcher's current privilege
+level. A blocked network request, incomplete release or checksum mismatch leaves the running version
+intact and is reported when Update is selected. Startup network failures remain non-interactive.
+The helper uses Windows' built-in Windows PowerShell 5.1; no additional runtime is installed.
+
+Settings and the other utility windows use the destination monitor's DPI for their initial frame,
+controls and fonts. They can be resized, stay within a remaining monitor's work area after display
+changes, and provide scrollbars when their content does not fit. Tab navigation scrolls the focused
+field into view; Shift+wheel scrolls horizontally.
+
 ## Implemented
 
 - Installed Windows keyboard layouts, configurable cycle/order and direct shortcuts; IMEs are switch-only.
@@ -45,7 +87,7 @@ Ctrl+Alt+Delete and Win+L; these cannot be assigned.
 - Clipboard snapshot/restoration with concurrent-copy, foreground and input-version checks.
 - Case cycling, Russian/Ukrainian transliteration, verified undo and repeated conversion.
 - Text snippets across layouts, multiline insertion and a verified `{cursor}` position;
-  `{{cursor}}` inserts the literal marker. Snippets are stored as plaintext settings, as in Typlo.
+  `{{cursor}}` inserts the literal marker. Snippets are stored as plaintext settings, as in [Typlo](https://github.com/bitcodepro/Typlo).
 - Clipboard history for text, HTML/RTF, file lists, DIB and PNG images; plain-text paste;
   full-text search, pinning, deletion, full text viewing and image previews.
 - Image thumbnails and text/file icons appear directly in the history list. Only visible rows
@@ -65,7 +107,7 @@ Ctrl+Alt+Delete and Win+L; these cannot be assigned.
 - Single instance and `--history`, `--convert`, `--case`, `--transliterate`, `--settings`,
   `--snippets`, `--exit` commands. `--convert` cycles layouts.
 
-Default shortcuts match Typlo: Ctrl+Alt+Shift+Space (cycle), C (case), T (transliteration),
+Default shortcuts match [Typlo](https://github.com/bitcodepro/Typlo): Ctrl+Alt+Shift+Space (cycle), C (case), T (transliteration),
 Z (undo), 1/2/3 (first layouts), and Ctrl+Shift+V (history).
 
 History controls: Enter to paste, Shift+Enter for plain text, Ctrl+1…9 for quick paste,
@@ -77,23 +119,43 @@ Pressing the history shortcut a second time pastes the second-most-recent item.
 Data is in `data/` beside the executable, falling back to `%LOCALAPPDATA%/KSwitcher` when
 the executable's directory is not writable. Each clipboard payload is an encrypted disk file;
 only bounded previews/metadata stay in memory. Image data is loaded on demand and released when
-the history popup is hidden. The log contains operational messages, never copied text or keystrokes.
+the history popup is hidden. Settings **Write log** (`writeLog`, enabled by default) controls all
+log writes. Disabling it also clears diagnostic context from memory; existing log files remain.
+Successful operations stay in a memory buffer of at most 40 diagnostic events for 30 seconds.
+Only failures flush this context to `kswitcher.log`; flushed
+context is discarded. Ordinary application errors are also logged when logging is enabled.
+Incident context contains tracked physical input, the expected word, copied text, conversion result,
+and layout IDs, correlated by request ID even when verification fails. Text fields use quoted,
+escaped UTF-16 (`\uXXXX` for non-ASCII and control characters) for exact reproduction, with
+original length and a truncation flag; each field is limited to 512 UTF-16 code units.
+Manual conversion attempts in `kswitcher.log` have request IDs and explicit outcomes, including
+busy, empty copy, verification mismatch, unchanged conversion, and cancelled paste. Requests
+record the process, window, input version, and repeated attempts within ten seconds without new
+input. Successful repeated commands do not flush the log; intentional layout cycling is normal.
+An unchanged result containing no letters, or a direct command
+to the detected current layout, is treated as expected. `paste-sent-unverified` means Windows
+accepted the paste shortcut; it does not prove that the editor applied the replacement.
+The previous 256 KiB log is retained as `kswitcher.log.1` when the current log rotates.
+Open **View log…** from Settings or the tray menu to read logs inside KSwitcher.
+Choose the current or previous log and press **Refresh** to reload. The ListView shows Time,
+Attempt, Event, and Details columns. Select rows and use **Copy selected** or Ctrl+C to copy
+tab-separated entries; Ctrl+A selects all rows. Viewing saved logs also works when logging is disabled.
+**Clear log** clears only the selected current or previous file and refreshes the table.
+Clearing the current log also discards buffered diagnostic context; new problems can still be logged.
 
-Settings **Import** accepts a Typlo `settings.json`, preserving supported Windows layout IDs,
-hotkeys, snippets, exclusions and limits. Import is staged until Save. Existing Typlo files are
-never modified. Typlo's encrypted SQLite history is **not migrated** to the new DPAPI file format.
+Settings **Import** accepts a [Typlo](https://github.com/bitcodepro/Typlo) `settings.json`, preserving supported Windows layout IDs,
+hotkeys, snippets, exclusions and limits. Import is staged until Save. Existing [Typlo](https://github.com/bitcodepro/Typlo) files are
+never modified. [Typlo](https://github.com/bitcodepro/Typlo)'s encrypted SQLite history is **not migrated** to the new DPAPI file format.
 DPAPI data belongs to the Windows account/machine; copying the portable folder is not a cross-account backup.
 
 ## Differences still to port
 
 This is a working native implementation, not a claim of complete UI/release parity:
 
-- UI currently uses English and the native Windows control appearance. Typlo's ten-language UI and
+- UI currently uses English and the native Windows control appearance. [Typlo](https://github.com/bitcodepro/Typlo)'s ten-language UI and
   explicit light/dark theme selector are not yet ported.
-- Automatic release download/replacement is not enabled. KSwitcher has no configured release feed;
-  using Typlo's feed would install the wrong application. Updates are manual.
 - No import of old encrypted clipboard history. Export/import applies to settings.
-- The clipboard popup is fixed-size with per-monitor DPI scaling; PNG/DIB previews use Windows WIC/GDI.
+- The clipboard popup uses per-monitor DPI scaling and scrolls when space is limited; PNG/DIB previews use Windows WIC/GDI.
 
 The Windows focus/injection rules still apply: an unelevated process cannot edit an elevated app.
 Conversion is cancelled rather than pasting into a different window or replacing unverified recent text.
@@ -175,8 +237,21 @@ Run `./package.ps1 -PublishRelease` after building and testing to refresh the tr
 .\build.ps1 -Test          # Pure/native regression checks; does not touch the user's clipboard
 .\build.ps1 -Ocr           # Render a synthetic image, decode it with WIC and recognize it with Windows OCR
 .\build.ps1 -Integration   # Interactive, isolated test editor; avoid input for about 10 seconds
+.\tests\configuration.ps1 # Separate-process settings tests; close KSwitcher first
 ```
 
+`-Test` also checks remote/own input separation, hidden Settings layout and scrolling, and updater
+package validation, file preservation and rollback in temporary fixture directories. It does not
+replace a running installation. Optional read-only network checks:
+
+```powershell
+.\build\KSwitcherInputTests.exe --update-check
+powershell.exe -NoProfile -ExecutionPolicy Bypass -File .\tests\update.ps1 -Network
+```
+
+These validate the live release metadata/download/checksum in a temporary directory. They do not
+prove hardware interoperability between two laptops or a physical monitor-disconnection sequence.
+
 The interactive test requires installed English-US and Russian layouts. It opens its own editor,
 tests real copy/paste, undo, repeat conversion, recent-input verification and snippet cursor placement,
 then restores the clipboard. Test data is stored in its own temporary directory. It never sends messages
@@ -191,9 +266,10 @@ It still uses the normal instance lock; close a running KSwitcher first if measu
 - `platform.*`: Win32 layouts, clipboard, input, ownership, DPAPI and file primitives.
 - `storage.*`: settings and encrypted, disk-backed history.
 - `app.*`: message loop, hooks, background work and guarded text transactions.
+- `config_main.cpp`, `configuration.*`: single-instance configurator and validated settings IPC.
 - `ui.cpp`: native windows and shortcut recording.
 - `ocr.*`: Windows WIC and OCR via the native Windows Runtime ABI.
 - `tests/`: regression checks, real editor integration and OCR fixture.
 
-Application code is MIT licensed; preserves the original Typlo attribution in `LICENSE`.
+Application code is MIT licensed; preserves the original [Typlo](https://github.com/bitcodepro/Typlo) attribution in `LICENSE`.
 Dictionary data has its own CC BY-SA 4.0 license as described above.

Release/README.md

@@ -1,21 +1,32 @@
 # Latest Windows release
 
-Download **KSwitcher-win-x64.zip**, extract the entire archive to a writable folder,
-and launch `KSwitcher.exe`. Keep `dictionaries/` next to the executable.
-The archive contains the application, offline dictionaries, documentation and license notices.
-It does not contain personal settings or clipboard history.
+## v0.3.0 — 2026-10-28
 
-For upgrades, exit KSwitcher first. Back up any edited dictionaries before replacing files.
-Keep your existing `data/` directory to retain settings and clipboard history.
-`SHA256SUMS.txt` contains the checksum of the archive.
+- Move Settings and the snippet editor into the on-demand `KSwitcher.Config.exe` process.
+- Repeated launches activate the existing configurator. Closing its last window releases the process and its memory.
+- Apply settings immediately through validated IPC with the resident process; reject conflicting saves instead of overwriting newer settings.
+- Keep shortcut capture in the resident hook, with no extra global hooks in the configurator.
+- Support packaging, validation and rollback of both executables. About now displays the actual application version.
 
-This folder holds only the latest compiled version; older versions remain in Git history.
+Verified: 170 native checks, 51 input/layout checks, 28 updater/metadata checks and 21 configurator process checks.
+A local before/after measurement after opening and closing Settings reduced resident working set from about 21.0 MiB to 14.7 MiB. Results vary; total memory is higher while the separate configurator is open.
 
-To refresh it from source:
+**Upgrade from v0.2.3 or earlier: install this release manually once.** The old updater rejects the additional EXE.
+Exit KSwitcher, extract the entire ZIP into the installation folder, and retain `data/` and any customized dictionaries.
+Keep `KSwitcher.exe`, `KSwitcher.Config.exe` and `dictionaries/` together. Launch `KSwitcher.exe`.
+Subsequent updates support both executables through the tray Update menu.
+
+Download **KSwitcher-win-x64.zip**. The archive contains both applications, offline dictionaries,
+documentation and license notices. It does not contain personal settings or clipboard history.
+`SHA256SUMS.txt` contains the archive checksum.
+
+This folder holds the latest compiled version; older versions remain in Git history and Releases.
+To refresh the tracked package from source:
 
 ```powershell
 .\build.ps1 -Stage -Test
 .\package.ps1 -PublishRelease
 ```
 
-Commit the updated ZIP and checksum together with the corresponding source changes.
+Commit the ZIP and checksum together with their source changes. Publish both files as assets of
+one stable release tagged with the executable version, so the updater can verify it.

Release/SHA256SUMS.txt

@@ -1 +1 @@
-906de70d92045cc6ff50802841cc357c6b47536fa0cbbb63301d779b33179469  KSwitcher-win-x64.zip
+104c79b64bb30a2161e3ec2f5108a731da0d274e015d53d8835ea7e64f431ee1  KSwitcher-win-x64.zip

build.ps1

@@ -14,24 +14,38 @@ Push-Location $root
 try {
     $common = @('-std=c++20','-Os','-DNDEBUG','-DUNICODE','-D_UNICODE','-DWIN32_LEAN_AND_MEAN','-DNOMINMAX','-D_WIN32_WINNT=0x0A00','-Wall','-Wextra','-Wno-missing-field-initializers','-Isrc','-Ivendor','-ffunction-sections','-fdata-sections')
     $libs = @('-luser32','-lshell32','-ladvapi32','-lcrypt32','-limm32','-lcomctl32','-lgdi32','-lole32','-loleaut32','-ltaskschd','-lcomdlg32','-luuid','-lwindowscodecs','-lruntimeobject','-luiautomationcore')
-    foreach ($name in @('core','platform','autostart','autocorrect','storage','ocr','richtext','app','ui','main')) {
+    foreach ($name in @('core','platform','autostart','autocorrect','storage','ocr','richtext','update','app','ui','main','configuration','config_main')) {
         & $compiler @common -c "src/$name.cpp" -o "build/$name.o"
         if ($LASTEXITCODE) { throw "Compilation failed: $name" }
     }
-    & windres resources/app.rc -O coff -o build/app-res.o
+    & $compiler @common -DKS_RESIDENT_APP -c src/ui.cpp -o build/ui-resident.o
+    if ($LASTEXITCODE) { throw 'Resident UI compilation failed' }
+    & $compiler @common -DKS_CONFIG_APP -c src/ui.cpp -o build/ui-config.o
+    if ($LASTEXITCODE) { throw 'Configurator UI compilation failed' }
+    & windres --codepage=65001 resources/app.rc -O coff -o build/app-res.o
     if ($LASTEXITCODE) { throw 'Resource compilation failed' }
     New-Item -ItemType Directory -Force build/release | Out-Null
-    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/app.o build/ui.o build/main.o build/app-res.o @libs -o $executablePath
+    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/app.o build/configuration.o build/ui-resident.o build/main.o build/app-res.o @libs -o $executablePath
     if ($LASTEXITCODE) { throw 'Link failed' }
     Copy-Item -LiteralPath $executablePath -Destination build/release/KSwitcher.exe -Force
+    $configPath = Join-Path (Split-Path $executablePath) 'KSwitcher.Config.exe'
+    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/storage.o build/ocr.o build/configuration.o build/config_main.o build/ui-config.o build/app-res.o @libs -o $configPath
+    if ($LASTEXITCODE) { throw 'Configurator link failed' }
+    Copy-Item -LiteralPath $configPath -Destination build/release/KSwitcher.Config.exe -Force
     if ($Test) {
-        & $compiler @common tests/tests.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o @libs -static -s -o build/KSwitcherTests.exe
+        & $compiler @common tests/tests.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o @libs -static -s -o build/KSwitcherTests.exe
         if ($LASTEXITCODE) { throw 'Test build failed' }
         & .\build\KSwitcherTests.exe
         if ($LASTEXITCODE) { throw 'Tests failed' }
+        & $compiler @common tests/input.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/app.o build/configuration.o build/ui.o build/app-res.o @libs -static -s -o build/KSwitcherInputTests.exe
+        if ($LASTEXITCODE) { throw 'Input test build failed' }
+        & .\build\KSwitcherInputTests.exe
+        if ($LASTEXITCODE) { throw 'Input tests failed' }
+        & "$env:SystemRoot\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -ExecutionPolicy Bypass -File tests/update.ps1 -Executable $executablePath
+        if ($LASTEXITCODE) { throw 'Updater tests failed' }
     }
     if ($Integration) {
-        & $compiler @common tests/integration.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/app.o build/ui.o build/app-res.o @libs -static -s -o build/KSwitcherIntegration.exe
+        & $compiler @common tests/integration.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/app.o build/configuration.o build/ui.o build/app-res.o @libs -static -s -o build/KSwitcherIntegration.exe
         if ($LASTEXITCODE) { throw 'Integration test build failed' }
         & .\build\KSwitcherIntegration.exe
         if ($LASTEXITCODE) { throw 'Integration tests failed' }

package.ps1

@@ -4,12 +4,13 @@ $root = $PSScriptRoot
 $destination = Join-Path $root 'dist\KSwitcher'
 New-Item -ItemType Directory -Force $destination | Out-Null
 Copy-Item -LiteralPath (Join-Path $root 'build\release\KSwitcher.exe') -Destination $destination
+Copy-Item -LiteralPath (Join-Path $root 'build\release\KSwitcher.Config.exe') -Destination $destination
 Copy-Item -LiteralPath (Join-Path $root 'LICENSE') -Destination $destination
 Copy-Item -LiteralPath (Join-Path $root 'vendor\json-LICENSE.txt') -Destination $destination
 Copy-Item -LiteralPath (Join-Path $root 'README.md') -Destination $destination
 Copy-Item -LiteralPath (Join-Path $root 'dictionaries') -Destination $destination -Recurse -Force
 # Enumerate the distributable files explicitly; do not include a user's data directory.
-$files = @('KSwitcher.exe','LICENSE','json-LICENSE.txt','README.md','dictionaries') | ForEach-Object { Join-Path $destination $_ }
+$files = @('KSwitcher.exe','KSwitcher.Config.exe','LICENSE','json-LICENSE.txt','README.md','dictionaries') | ForEach-Object { Join-Path $destination $_ }
 $archive = Join-Path $root 'dist\KSwitcher-win-x64.zip'
 Compress-Archive -LiteralPath $files -DestinationPath $archive -Force
 Get-FileHash -LiteralPath $archive -Algorithm SHA256

resources/app.rc

@@ -1,10 +1,12 @@
+#pragma code_page(65001)
 #include <windows.h>
 #include "resource.h"
 IDI_KSWITCHER ICON "kswitcher.ico"
 1 RT_MANIFEST "app.manifest"
+201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,1,0,0
- PRODUCTVERSION 0,1,0,0
+ FILEVERSION 0,3,0,0
+ PRODUCTVERSION 0,3,0,0
  FILEOS VOS_NT_WINDOWS32
  FILETYPE VFT_APP
 BEGIN
@@ -14,7 +16,7 @@ BEGIN
   BEGIN
    VALUE "FileDescription", "KSwitcher — native keyboard and clipboard utility"
    VALUE "ProductName", "KSwitcher"
-   VALUE "FileVersion", "0.1.0"
+   VALUE "FileVersion", "0.3.0"
   END
  END
  BLOCK "VarFileInfo"

resources/update.ps1

@@ -0,0 +1,217 @@
+param(
+    [ValidateSet('Check','Install')][string]$Mode = 'Check',
+    [string]$CurrentVersion, [string]$ExpectedVersion,
+    [string]$InstallDirectory, [string]$WorkDirectory,
+    [int]$ParentProcessId, [string]$ReadyEvent,
+    [switch]$Library
+)
+$ErrorActionPreference = 'Stop'
+Set-StrictMode -Version Latest
+
+function Get-StableVersion([string]$Tag) {
+    if ($Tag -notmatch '^v?(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$') { return $null }
+    try { return [version]($Tag -replace '^v','') } catch { return $null }
+}
+function Assert-ReleaseUrl([string]$Url) {
+    $uri = [uri]$Url
+    if (!$uri.IsAbsoluteUri -or $uri.Scheme -ne 'https' -or $uri.Host -ne 'gitea.hrynco.com' -or
+        !$uri.IsDefaultPort -or $uri.UserInfo -or $uri.Query -or $uri.Fragment -or
+        !$uri.AbsolutePath.StartsWith('/hrynco/hrynco-kswitcher/releases/download/',[StringComparison]::Ordinal)) {
+        throw 'Release asset URL is outside the KSwitcher repository.'
+    }
+}
+function Receive-File([string]$Url,[string]$Path,[long]$Limit) {
+    [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
+    $request = [Net.HttpWebRequest]::Create($Url)
+    $request.AllowAutoRedirect = $false
+    $request.Timeout = 15000
+    $request.ReadWriteTimeout = 15000
+    $request.UserAgent = 'KSwitcher-Updater'
+    $response = $null; $inputStream = $null; $outputStream = $null
+    try {
+        $response = $request.GetResponse()
+        if ([int]$response.StatusCode -ne 200 -or $response.ContentLength -gt $Limit) { throw 'Invalid or oversized server response.' }
+        $inputStream = $response.GetResponseStream()
+        $outputStream = [IO.File]::Create($Path)
+        $buffer = New-Object byte[] 65536
+        $total = 0L
+        $deadline = [DateTime]::UtcNow.AddSeconds(60)
+        while (($count = $inputStream.Read($buffer,0,$buffer.Length)) -gt 0) {
+            $total += $count
+            if ($total -gt $Limit -or [DateTime]::UtcNow -gt $deadline) { throw 'Download exceeded size or time limit.' }
+            $outputStream.Write($buffer,0,$count)
+        }
+    } finally {
+        if ($outputStream) { $outputStream.Dispose() }
+        if ($inputStream) { $inputStream.Dispose() }
+        if ($response) { $response.Dispose() }
+    }
+}
+function Select-Release($Releases,[version]$Current) {
+    $candidates = @($Releases | Where-Object { !$_.draft -and !$_.prerelease -and (Get-StableVersion $_.tag_name) } |
+        Sort-Object { Get-StableVersion $_.tag_name } -Descending)
+    if (!$candidates.Count -or (Get-StableVersion $candidates[0].tag_name) -le $Current) { return $null }
+    $release = $candidates[0]
+    $zip = @($release.assets | Where-Object name -CEQ 'KSwitcher-win-x64.zip')
+    $sum = @($release.assets | Where-Object name -CEQ 'SHA256SUMS.txt')
+    if ($zip.Count -ne 1 -or $sum.Count -ne 1) { throw 'The newest release lacks its x64 ZIP or SHA256SUMS.txt.' }
+    Assert-ReleaseUrl $zip[0].browser_download_url
+    Assert-ReleaseUrl $sum[0].browser_download_url
+    return @{ version=$release.tag_name; zip=$zip[0].browser_download_url; checksum=$sum[0].browser_download_url }
+}
+function Assert-Checksum([string]$Archive,[string]$Checksum) {
+    $matchesFound = @([IO.File]::ReadAllLines($Checksum) | Where-Object { $_ -cmatch '^([a-fA-F0-9]{64})\s+\*?KSwitcher-win-x64\.zip$' })
+    if ($matchesFound.Count -ne 1) { throw 'Missing or ambiguous archive checksum.' }
+    $expected = ($matchesFound[0] -split '\s+')[0]
+    if ((Get-FileHash -LiteralPath $Archive -Algorithm SHA256).Hash -ne $expected) { throw 'Release checksum verification failed.' }
+}
+function Expand-Release([string]$Archive,[string]$Destination,[version]$Expected) {
+    Add-Type -AssemblyName System.IO.Compression.FileSystem
+    $zip = [IO.Compression.ZipFile]::OpenRead($Archive)
+    try {
+        $seen = [Collections.Generic.HashSet[string]]::new([StringComparer]::OrdinalIgnoreCase)
+        $total = 0L
+        foreach ($entry in $zip.Entries) {
+            $name = $entry.FullName.Replace('\','/')
+            if ($name.EndsWith('/') -and $name -eq 'dictionaries/') { continue }
+            if ($name -cnotmatch '^(KSwitcher(?:\.Config)?\.exe|LICENSE|json-LICENSE\.txt|README\.md|dictionaries/[a-zA-Z0-9_.-]+)$' -or
+                $name.EndsWith('/.') -or $name.EndsWith('/..') -or $name.EndsWith('.') -or
+                (($entry.ExternalAttributes -shr 16) -band 0xF000) -eq 0xA000 -or !$seen.Add($name)) {
+                throw "Unexpected or unsafe archive entry: $name"
+            }
+            $total += $entry.Length
+            if ($total -gt 100MB -or $zip.Entries.Count -gt 100) { throw 'Release expands beyond allowed limits.' }
+            $destinationFile = Join-Path $Destination $name
+            [IO.Directory]::CreateDirectory([IO.Path]::GetDirectoryName($destinationFile)) | Out-Null
+            [IO.Compression.ZipFileExtensions]::ExtractToFile($entry,$destinationFile,$false)
+        }
+        foreach ($required in @('KSwitcher.exe','LICENSE','json-LICENSE.txt','README.md')) {
+            if (!$seen.Contains($required)) { throw "Incomplete release: $required" }
+        }
+        if ($Expected -gt [version]'0.2.3' -and !$seen.Contains('KSwitcher.Config.exe')) {
+            throw 'Incomplete release: KSwitcher.Config.exe'
+        }
+    } finally { $zip.Dispose() }
+    foreach ($binary in @('KSwitcher.exe','KSwitcher.Config.exe')) {
+    $exe = Join-Path $Destination $binary
+    if (!(Test-Path -LiteralPath $exe)) { continue }
+    $version = [Diagnostics.FileVersionInfo]::GetVersionInfo($exe)
+    if ($version.ProductName -ne 'KSwitcher' -or (Get-StableVersion $version.FileVersion) -ne $Expected) {
+        throw 'Executable identity/version does not match the release.'
+    }
+    $bytes = [IO.File]::ReadAllBytes($exe)
+    if ($bytes.Length -lt 64 -or $bytes[0] -ne 0x4d -or $bytes[1] -ne 0x5a) { throw 'Invalid release executable.' }
+    $pe = [BitConverter]::ToInt32($bytes,60)
+    if ($pe -lt 64 -or $pe -gt $bytes.Length-6 -or [BitConverter]::ToUInt32($bytes,$pe) -ne 0x4550 -or
+        [BitConverter]::ToUInt16($bytes,$pe+4) -ne 0x8664) { throw 'Release is not a Windows x64 executable.' }
+    }
+}
+function Assert-PlainDirectory([string]$Directory) {
+    $item = Get-Item -LiteralPath $Directory -Force
+    while ($item) {
+        if ($item.Attributes -band [IO.FileAttributes]::ReparsePoint) { throw 'Update directory must not contain junctions or symbolic links.' }
+        $item = $item.Parent
+    }
+}
+function Install-Files([string]$Stage,[string]$Target,[string]$Backup,[Collections.Generic.List[string]]$Changed) {
+    Assert-PlainDirectory $Target
+    foreach ($file in @(Get-ChildItem -LiteralPath $Stage -File -Recurse)) {
+        $relative = $file.FullName.Substring($Stage.Length+1)
+        $destination = Join-Path $Target $relative
+        if ($relative.StartsWith('dictionaries\') -and (Test-Path -LiteralPath $destination)) { continue }
+        [IO.Directory]::CreateDirectory([IO.Path]::GetDirectoryName($destination)) | Out-Null
+        Assert-PlainDirectory ([IO.Path]::GetDirectoryName($destination))
+        if (Test-Path -LiteralPath $destination) {
+            if ((Get-Item -LiteralPath $destination -Force).Attributes -band [IO.FileAttributes]::ReparsePoint) { throw 'Cannot replace a linked file.' }
+            $backupFile = Join-Path $Backup $relative
+            [IO.Directory]::CreateDirectory([IO.Path]::GetDirectoryName($backupFile)) | Out-Null
+            Move-Item -LiteralPath $destination -Destination $backupFile
+        }
+        $Changed.Add($relative)
+        Move-Item -LiteralPath $file.FullName -Destination $destination
+    }
+}
+function Undo-Files([string]$Target,[string]$Backup,[Collections.Generic.List[string]]$Changed) {
+    for ($i=$Changed.Count-1; $i -ge 0; --$i) {
+        $destination = Join-Path $Target $Changed[$i]
+        if (Test-Path -LiteralPath $destination) { Remove-Item -LiteralPath $destination -Force }
+        $original = Join-Path $Backup $Changed[$i]
+        if (Test-Path -LiteralPath $original) { Move-Item -LiteralPath $original -Destination $destination }
+    }
+}
+function Write-Result($Value) {
+    $Value | ConvertTo-Json -Compress | Set-Content -LiteralPath (Join-Path $WorkDirectory 'result.json') -Encoding UTF8
+}
+if ($Library) { return }
+$transaction = $null; $parentProcess = $null; $ready = $null; $started = $null
+$changed = [Collections.Generic.List[string]]::new()
+$parentExited = $false; $success = $false; $preserveBackup = $false; $child = $null
+try {
+    $current = Get-StableVersion $CurrentVersion
+    if (!$current) { throw 'Invalid installed version.' }
+    if ($Mode -eq 'Install') {
+        $parentProcess = Get-Process -Id $ParentProcessId
+        if ([IO.Path]::GetFullPath($parentProcess.Path) -ne [IO.Path]::GetFullPath((Join-Path $InstallDirectory 'KSwitcher.exe'))) {
+            throw 'The running executable does not match the update target.'
+        }
+        $ready = [Threading.EventWaitHandle]::OpenExisting($ReadyEvent)
+    }
+    $metadata = Join-Path $WorkDirectory 'releases.json'
+    Receive-File 'https://gitea.hrynco.com/api/v1/repos/hrynco/hrynco-kswitcher/releases?limit=100' $metadata 2MB
+    $release = Select-Release (Get-Content -LiteralPath $metadata -Raw | ConvertFrom-Json) $current
+    if (!$release) { Write-Result @{state='current'}; exit 0 }
+    if ($Mode -eq 'Check') { Write-Result @{state='available';version=$release.version}; exit 0 }
+    if ($ExpectedVersion -ne $release.version) { throw 'Release changed since checking. Please select Update again.' }
+    Assert-PlainDirectory $InstallDirectory
+    $transaction = Join-Path $InstallDirectory ('.kswitcher-update-'+[guid]::NewGuid().ToString('N'))
+    $stage = Join-Path $transaction 'stage'; $backup = Join-Path $transaction 'backup'
+    [IO.Directory]::CreateDirectory($stage) | Out-Null
+    $archive = Join-Path $WorkDirectory 'release.zip'; $checksum = Join-Path $WorkDirectory 'SHA256SUMS.txt'
+    Receive-File $release.zip $archive 50MB
+    Receive-File $release.checksum $checksum 64KB
+    Assert-Checksum $archive $checksum
+    Expand-Release $archive $stage (Get-StableVersion $release.version)
+    Write-Result @{state='prepared';version=$release.version}
+    $ready.Set() | Out-Null
+    if (!$parentProcess.WaitForExit(120000)) { throw 'KSwitcher did not exit; the installed files were not changed.' }
+    $parentExited = $true
+    Install-Files $stage $InstallDirectory $backup $changed
+    $startedName = 'Local\KSwitcher.Update.Started.'+[guid]::NewGuid().ToString('N')
+    $started = [Threading.EventWaitHandle]::new($false,[Threading.EventResetMode]::ManualReset,$startedName)
+    $child = Start-Process -FilePath (Join-Path $InstallDirectory 'KSwitcher.exe') -ArgumentList "--update-ready-event=$startedName" -WorkingDirectory $InstallDirectory -WindowStyle Hidden -PassThru
+    if (!$started.WaitOne(30000) -or $child.HasExited) { throw 'The updated application did not confirm startup.' }
+    $success = $true
+} catch {
+    $message = $_.Exception.Message
+    if ($parentExited) {
+        try {
+            if ($child -and !$child.HasExited) { $child.Kill(); $child.WaitForExit() }
+            Undo-Files $InstallDirectory $backup $changed
+            Start-Process -FilePath (Join-Path $InstallDirectory 'KSwitcher.exe') -WorkingDirectory $InstallDirectory -WindowStyle Hidden
+            $message += "`nThe previous version has been restored and restarted."
+        } catch {
+            $preserveBackup = $true
+            $message += "`nRecovery needs attention: $($_.Exception.Message)`nBackup: $backup"
+        }
+    }
+    Write-Result @{state='error';error=$message}
+    if ($ready -and $ready.WaitOne(0)) {
+        Add-Type -AssemblyName System.Windows.Forms
+        [Windows.Forms.MessageBox]::Show($message,'KSwitcher update failed') | Out-Null
+    }
+    exit 1
+} finally {
+    if ($ready) { $ready.Dispose() }
+    if ($started) { $started.Dispose() }
+    if ($parentProcess) { $parentProcess.Dispose() }
+    # Only remove the uniquely created transaction directory directly under the install directory.
+    if ($transaction -and !$preserveBackup -and [IO.Path]::GetDirectoryName($transaction) -eq [IO.Path]::GetFullPath($InstallDirectory).TrimEnd('\') -and (Test-Path -LiteralPath $transaction)) {
+        Remove-Item -LiteralPath $transaction -Recurse -Force -ErrorAction SilentlyContinue
+    }
+    if ($success) {
+        # The script is loaded in memory; its unique temporary working directory is no longer needed.
+        if ((Split-Path -Leaf $WorkDirectory) -like 'KSwitcher-update-*' -and [IO.Path]::GetDirectoryName($WorkDirectory) -eq [IO.Path]::GetTempPath().TrimEnd('\')) {
+            Remove-Item -LiteralPath $WorkDirectory -Recurse -Force -ErrorAction SilentlyContinue
+        }
+    }
+}

src/app.cpp

@@ -1,6 +1,7 @@
 #include "app.h"
 #include "../resources/resource.h"
 #include "ocr.h"
+#include "configuration.h"
 #include <algorithm>
 #include <commctrl.h>
 #include <set>
@@ -125,7 +126,10 @@ class Transaction
         write(textClip(L"\x2063KSwitcher-" + std::to_wstring(GetTickCount64())));
         DWORD before = expected;
         if (!valid() || !chord(L'C', MOD_CONTROL))
+        {
+            diagnosticEvent(L"Copy failed: context changed or simulated Ctrl+C blocked");
             return {};
+        }
         ULONGLONG deadline = GetTickCount64() + 2000;
         DWORD changed = before;
         ULONGLONG stable = 0;
@@ -146,7 +150,11 @@ class Transaction
             Sleep(10);
         }
         if (changed == before || !valid())
+        {
+            diagnosticEvent(changed == before ? L"Copy failed: clipboard timeout (2000 ms)" :
+                                    L"Copy failed: context changed");
             return {};
+        }
         if ((GetClipboardOwner() ? !ownsClipboard(target) : changedAgain) ||
             changed != GetClipboardSequenceNumber())
             throw std::runtime_error("Operation cancelled: copy did not belong to the target application");
@@ -159,13 +167,19 @@ class Transaction
         {
             if (f.name == L"VisualStudioEditorOperationsLineCutCopyClipboardTag" ||
                 f.name == L"MSDEVLineSelect")
+            {
+                diagnosticEvent(L"Copy rejected: editor copied line without selection");
                 return {};
+            }
             if (f.name == L"vscode-editor-data")
             {
                 std::string json(f.data.begin(), f.data.end());
                 if (json.find("\"isFromEmptySelection\":true") != json.npos ||
                     json.find("\"isFromEmptySelection\": true") != json.npos)
+                {
+                    diagnosticEvent(L"Copy rejected: editor reported empty selection");
                     return {};
+                }
             }
         }
         return text;
@@ -188,7 +202,7 @@ class Transaction
             auto text = copy();
             if (valid() && matches(text))
             {
-                log(L"Selection: verified word boundary");
+                diagnosticEvent(L"Selection: verified word boundary");
                 return text;
             }
             if (!valid() || !chord(VK_RIGHT))
@@ -230,6 +244,7 @@ App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instan
         settings = loadSettings(data / L"missing-defaults.json", layouts);
         registrationWarning = L"Settings were not loaded: " + wide(e.what());
     }
+    setLoggingEnabled(settings.writeLog);
     try
     {
         history = std::make_unique<History>(data / L"history");
@@ -242,6 +257,8 @@ App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instan
 }
 App::~App()
 {
+    if (updateWorker.joinable())
+        updateWorker.join();
     if (keyboardHook)
         UnhookWindowsHookEx(keyboardHook);
     if (mouseHook)
@@ -349,6 +366,7 @@ void App::applySettings(const Settings &s)
     {
         std::lock_guard lock(stateMutex);
         settings = s;
+        setLoggingEnabled(s.writeLog);
         run.reset();
         last.reset();
         ++inputVersion;
@@ -381,6 +399,18 @@ void App::reloadLayouts()
     }
     registerHotkeys(settings);
 }
+void App::clearHistory()
+{
+    if (busy) throw std::runtime_error("Wait for the current operation to finish.");
+    if (history) history->clear();
+    if (historyWindow) refreshHistory(*this);
+}
+void App::setHotkeyCapture(HWND field)
+{
+    hotkeyCapture = field;
+    hotkeyCaptureProcess = 0;
+    if (field) GetWindowThreadProcessId(field, &hotkeyCaptureProcess);
+}
 bool App::isHotkey(DWORD key, UINT mods)
 {
     for (auto &[id, text] : shortcuts(settings))
@@ -398,23 +428,15 @@ void App::resetInput()
     run.reset();
     last.reset();
 }
-void App::keyboard(const KBDLLHOOKSTRUCT &k)
+void App::keyboard(const KBDLLHOOKSTRUCT &k, UINT mods)
 {
-    if (k.flags & LLKHF_INJECTED)
+    if (ownKeyboardInput(k))
         return;
     DWORD vk = k.vkCode;
-    if (vk == VK_LSHIFT || vk == VK_RSHIFT || vk == VK_LCONTROL || vk == VK_RCONTROL || vk == VK_LMENU ||
+    if (vk == VK_SHIFT || vk == VK_CONTROL || vk == VK_MENU ||
+        vk == VK_LSHIFT || vk == VK_RSHIFT || vk == VK_LCONTROL || vk == VK_RCONTROL || vk == VK_LMENU ||
         vk == VK_RMENU || vk == VK_LWIN || vk == VK_RWIN)
         return;
-    UINT mods = 0;
-    if (GetAsyncKeyState(VK_CONTROL) & 0x8000)
-        mods |= MOD_CONTROL;
-    if (GetAsyncKeyState(VK_MENU) & 0x8000)
-        mods |= MOD_ALT;
-    if (GetAsyncKeyState(VK_SHIFT) & 0x8000)
-        mods |= MOD_SHIFT;
-    if ((GetAsyncKeyState(VK_LWIN) | GetAsyncKeyState(VK_RWIN)) & 0x8000)
-        mods |= MOD_WIN;
     std::lock_guard lock(stateMutex);
     if (isHotkey(vk, mods))
         return;
@@ -433,7 +455,11 @@ void App::keyboard(const KBDLLHOOKSTRUCT &k)
         return;
     }
     bool shift = (mods & MOD_SHIFT) != 0;
-    wchar_t ch = vk == VK_SPACE ? L' ' : physicalKey(k.scanCode, shift);
+    // VK_PACKET carries UTF-16 in scanCode, not a physical key position.
+    DWORD scan = vk == VK_PACKET ? 0 : k.scanCode;
+    if (!scan && vk != VK_PACKET)
+        scan = MapVirtualKeyExW(vk, MAPVK_VK_TO_VSC_EX, layout);
+    wchar_t ch = vk == VK_SPACE ? L' ' : physicalKey(scan, shift);
     if (ch && letter(ch) && (GetKeyState(VK_CAPITAL) & 1))
         ch = shift ? lower(std::wstring(1, ch))[0] : upper(std::wstring(1, ch))[0];
     if (!ch)
@@ -477,85 +503,87 @@ void App::keyboard(const KBDLLHOOKSTRUCT &k)
             }
     }
 }
-LRESULT CALLBACK App::keyProc(int code, WPARAM wp, LPARAM lp)
+bool App::handleKeyboard(const KBDLLHOOKSTRUCT &key, bool down, UINT mods)
 {
-    if (code == HC_ACTION && (((KBDLLHOOKSTRUCT *)lp)->flags & LLKHF_INJECTED) &&
-        ((KBDLLHOOKSTRUCT *)lp)->vkCode == 0xE8)
-        return CallNextHookEx(nullptr, code, wp, lp); // Our shell-mask key is never recorded.
-    if (code == HC_ACTION && current && current->hotkeyCapture &&
-        GetForegroundWindow() == GetAncestor(current->hotkeyCapture, GA_ROOT))
+    // Filter before capture, hotkey latching and typing history. External injected
+    // down AND up events use exactly the same path as physical keyboard input.
+    if (ownKeyboardInput(key) || installingUpdate)
+        return false;
+    DWORD captureProcess{};
+    if (hotkeyCapture) GetWindowThreadProcessId(hotkeyCapture, &captureProcess);
+    if (hotkeyCapture && (!captureProcess || captureProcess != hotkeyCaptureProcess))
+        setHotkeyCapture(nullptr);
+    if (hotkeyCapture && GetForegroundWindow() == GetAncestor(hotkeyCapture, GA_ROOT))
     {
-        auto &key = *(KBDLLHOOKSTRUCT *)lp;
-        bool modifier = key.vkCode == VK_LCONTROL || key.vkCode == VK_RCONTROL || key.vkCode == VK_LSHIFT ||
+        bool modifier = key.vkCode == VK_CONTROL || key.vkCode == VK_SHIFT || key.vkCode == VK_MENU ||
+                        key.vkCode == VK_LCONTROL || key.vkCode == VK_RCONTROL || key.vkCode == VK_LSHIFT ||
                         key.vkCode == VK_RSHIFT || key.vkCode == VK_LMENU || key.vkCode == VK_RMENU ||
                         key.vkCode == VK_LWIN || key.vkCode == VK_RWIN;
         if (!modifier)
         {
-            if (wp == WM_KEYUP || wp == WM_SYSKEYUP)
-                current->hotkeyHook.update(key.vkCode, false, 0, {});
-            if (wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN)
+            if (!down)
+                hotkeyHook.update(key.vkCode, false, 0, {});
+            if (down)
             {
-                UINT mods = 0;
-                if (GetAsyncKeyState(VK_CONTROL) & 0x8000)
-                    mods |= MOD_CONTROL;
-                if (GetAsyncKeyState(VK_MENU) & 0x8000)
-                    mods |= MOD_ALT;
-                if (GetAsyncKeyState(VK_SHIFT) & 0x8000)
-                    mods |= MOD_SHIFT;
-                if ((GetAsyncKeyState(VK_LWIN) | GetAsyncKeyState(VK_RWIN)) & 0x8000)
-                    mods |= MOD_WIN;
                 if (mods & MOD_WIN)
                     chord(0xE8);
-                PostMessageW(current->hotkeyCapture, CaptureHotkeyMessage, key.vkCode, mods);
+                PostMessageW(hotkeyCapture, CaptureHotkeyMessage, key.vkCode, mods);
             }
             return 1; // Record the chord without executing a global shortcut or typing into an editor.
         }
     }
-    if (code == HC_ACTION && (((KBDLLHOOKSTRUCT *)lp)->flags & LLKHF_INJECTED))
-        return CallNextHookEx(nullptr, code, wp, lp);
-    if (code == HC_ACTION && (wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN) && current)
+    if (down)
     {
-        auto &key = *(KBDLLHOOKSTRUCT *)lp;
-        UINT mods = 0;
-        if (GetAsyncKeyState(VK_CONTROL) & 0x8000)
-            mods |= MOD_CONTROL;
-        if (GetAsyncKeyState(VK_MENU) & 0x8000)
-            mods |= MOD_ALT;
-        if (GetAsyncKeyState(VK_SHIFT) & 0x8000)
-            mods |= MOD_SHIFT;
-        if ((GetAsyncKeyState(VK_LWIN) | GetAsyncKeyState(VK_RWIN)) & 0x8000)
-            mods |= MOD_WIN;
-        auto action = current->hotkeyHook.update(key.vkCode, true, mods, current->hookBindings);
+        auto action = hotkeyHook.update(key.vkCode, true, mods, hookBindings);
         if (action > 0)
         {
             // Tell the shell that Win participated in a chord, preventing Start
             // from opening on Win-up after we consumed V. 0xE8 is unassigned.
             if (mods & (MOD_WIN | MOD_ALT))
                 chord(0xE8);
-            PostMessageW(current->window, WM_HOTKEY, action, 0);
+            PostMessageW(window, WM_HOTKEY, action, 0);
         }
         if (action != 0)
             return 1;
-        current->keyboard(*(KBDLLHOOKSTRUCT *)lp);
+        keyboard(key, mods);
+    }
+    else if (hotkeyHook.update(key.vkCode, false, 0, hookBindings) != 0)
+        return true;
+    return false;
+}
+LRESULT CALLBACK App::keyProc(int code, WPARAM wp, LPARAM lp)
+{
+    if (code == HC_ACTION && current &&
+        (wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN || wp == WM_KEYUP || wp == WM_SYSKEYUP))
+    {
+        // The current event has not updated asynchronous state yet; the preceding
+        // modifier events (including MWB input) have. Own events must still reach Windows.
+        UINT mods = 0;
+        if (GetAsyncKeyState(VK_CONTROL) & 0x8000) mods |= MOD_CONTROL;
+        if (GetAsyncKeyState(VK_MENU) & 0x8000) mods |= MOD_ALT;
+        if (GetAsyncKeyState(VK_SHIFT) & 0x8000) mods |= MOD_SHIFT;
+        if ((GetAsyncKeyState(VK_LWIN) | GetAsyncKeyState(VK_RWIN)) & 0x8000) mods |= MOD_WIN;
+        if (current->handleKeyboard(*(KBDLLHOOKSTRUCT *)lp,
+                                    wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN, mods))
+            return 1;
     }
-    if (code == HC_ACTION && (wp == WM_KEYUP || wp == WM_SYSKEYUP) && current &&
-        current->hotkeyHook.update(((KBDLLHOOKSTRUCT *)lp)->vkCode, false, 0, current->hookBindings) != 0)
-        return 1;
     return CallNextHookEx(nullptr, code, wp, lp);
 }
 LRESULT CALLBACK App::mouseProc(int code, WPARAM wp, LPARAM lp)
 {
     if (code == HC_ACTION && current)
     {
-        auto *e = (MSLLHOOKSTRUCT *)lp;
-        if (!(e->flags & LLMHF_INJECTED) &&
-            (wp == WM_LBUTTONDOWN || wp == WM_RBUTTONDOWN || wp == WM_MBUTTONDOWN || wp == WM_MOUSEWHEEL))
+        // KSwitcher generates no mouse input. Remote clicks invalidate a typing
+        // range just like local clicks, including while a transaction is pending.
+        if (wp == WM_LBUTTONDOWN || wp == WM_RBUTTONDOWN || wp == WM_MBUTTONDOWN || wp == WM_MOUSEWHEEL)
             current->resetInput();
     }
     return CallNextHookEx(nullptr, code, wp, lp);
 }
 void App::dispatch(int command)
 {
+    if (installingUpdate)
+        return;
     try
     {
         if (command == ShowHistory)
@@ -568,6 +596,11 @@ void App::dispatch(int command)
             showSettings(*this);
             return;
         }
+        if (command == 22)
+        {
+            showLogs(*this);
+            return;
+        }
         if (command == 21)
         {
             showSnippets(*this);
@@ -587,9 +620,34 @@ void App::dispatch(int command)
 }
 void App::transform(int command, int snippet)
 {
-    if (busy.exchange(true))
-        return;
+    if (installingUpdate) return;
+    const auto attempt = ++transformAttempt;
+    const auto requestedAt = GetTickCount64();
     HWND target = GetForegroundWindow();
+    const bool manual = command != AutoCorrect && snippet < 0;
+    if (manual)
+    {
+        const auto currentVersion = inputVersion.load();
+        repeatAttempts = target == previousAttemptWindow && command == previousAttemptCommand &&
+                                 currentVersion == previousAttemptVersion &&
+                                 requestedAt - previousAttemptAt < 10000
+                             ? repeatAttempts + 1 : 1;
+        previousAttemptWindow = target;
+        previousAttemptCommand = command;
+        previousAttemptVersion = currentVersion;
+        previousAttemptAt = requestedAt;
+        diagnosticEvent(L"Transform request id=" + std::to_wstring(attempt) + L" command=" +
+            std::to_wstring(command) + L" process=" + processName(target) +
+            L" window=" + std::to_wstring(reinterpret_cast<uintptr_t>(target)) +
+            L" version=" + std::to_wstring(currentVersion) +
+            L" repeat=" + std::to_wstring(repeatAttempts));
+    }
+    if (busy.exchange(true))
+    {
+        if (manual)
+            diagnosticEvent(L"Transform outcome id=" + std::to_wstring(attempt) + L" reason=busy", true);
+        return;
+    }
     Run recent;
     std::optional<LastTransform> previous;
     Settings config;
@@ -604,7 +662,7 @@ void App::transform(int command, int snippet)
         version = inputVersion;
     }
     enqueue(
-        [this, target, recent, previous, config, available, version, command, snippet]
+        [this, target, recent, previous, config, available, version, command, snippet, attempt, manual, requestedAt]
         {
             struct BusyReset
             {
@@ -615,6 +673,47 @@ void App::transform(int command, int snippet)
                 }
             } reset{busy};
             auto start = GetTickCount64();
+            std::wstring reason = L"cancelled-before-selection";
+            std::wstring text, result, expected;
+            int hint = -1, to = command >= Direct ? command - Direct : -1;
+            if (manual)
+            {
+                std::wstring layoutIds;
+                for (const auto &layout : available)
+                {
+                    layoutIds += layout.id + L",";
+                    if (layout.handle == recent.layout)
+                        for (wchar_t key : recent.keys)
+                            expected += key == L' ' ? L' ' : layout.at(physicalLayout().code(key));
+                }
+                diagnosticEvent(L"Transform context id=" + std::to_wstring(attempt) +
+                    L" layouts=" + layoutIds + L" physicalKeys=" + diagnosticText(recent.keys) +
+                    L" trackedExpected=" + diagnosticText(expected));
+            }
+            struct Audit
+            {
+                App &app;
+                HWND target;
+                uint64_t version, attempt;
+                ULONGLONG start;
+                bool enabled;
+                std::wstring &reason;
+                std::wstring &text, &result, &expected;
+                int &hint, &to;
+                ~Audit()
+                {
+                    if (enabled)
+                        diagnosticEvent(L"Transform outcome id=" + std::to_wstring(attempt) + L" reason=" + reason +
+                            L" foregroundSame=" + std::to_wstring(GetForegroundWindow() == target) +
+                            L" inputSame=" + std::to_wstring(app.inputVersion.load() == version) +
+                            L" elapsedMs=" + std::to_wstring(GetTickCount64() - start) +
+                            L" source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
+                            L" expected=" + diagnosticText(expected) + L" copied=" + diagnosticText(text) +
+                            L" result=" + diagnosticText(result),
+                            reason != L"paste-sent-unverified" && reason != L"layout-only" &&
+                            reason != L"unchanged-expected");
+                }
+            } audit{*this, target, version, attempt, requestedAt, manual, reason, text, result, expected, hint, to};
             try
             {
                 auto valid = [&]
@@ -627,16 +726,16 @@ void App::transform(int command, int snippet)
                     releaseModifiers();
                 if (!valid())
                     return;
-                int hint = -1;
                 for (int i = 0; i < (int)available.size(); ++i)
                     if (available[i].handle == windowLayout(target))
                         hint = i;
-                int to = command >= Direct ? command - Direct : -1;
+                reason = L"invalid-target-layout";
                 if (to >= (int)available.size())
                     return;
                 if (to >= 0 && !available[to].convertible)
                 {
-                    switchWindowLayout(target, available[to].handle, valid);
+                    reason = switchWindowLayout(target, available[to].handle, valid)
+                                 ? L"layout-only" : L"layout-switch-failed";
                     return;
                 }
                 if (command == AutoCorrect)
@@ -654,12 +753,16 @@ void App::transform(int command, int snippet)
                         !autoCorrectionAllowed(target, config) || !valid())
                         return;
                 }
+                reason = L"clipboard-snapshot";
                 Transaction tx(*this, target, version);
-                log(L"Transform target=" + processName(target) + L" command=" + std::to_wstring(command) +
+                reason = L"selection-unavailable";
+                diagnosticEvent(L"Transform target=" + processName(target) + L" command=" + std::to_wstring(command) +
                     L" recent=" + std::to_wstring(config.recent) + L" keys=" +
                     std::to_wstring(recent.keys.size()) + L" sameWindow=" +
-                    std::to_wstring(recent.window == target));
-                std::wstring text, result;
+                    std::to_wstring(recent.window == target) + L" overflow=" +
+                    std::to_wstring(recent.overflow) + L" ageMs=" +
+                    std::to_wstring(recent.at ? start - recent.at : 0) +
+                    L" id=" + std::to_wstring(attempt));
                 bool automatic = false;
                 if (command == AutoCorrect)
                 {
@@ -692,6 +795,9 @@ void App::transform(int command, int snippet)
                 }
                 else if (command == Undo)
                 {
+                    if (previous)
+                        expected = previous->result;
+                    reason = L"undo-unavailable";
                     if (!previous || previous->window != target || previous->version != version ||
                         GetTickCount64() - previous->at > 120000)
                         return;
@@ -700,6 +806,7 @@ void App::transform(int command, int snippet)
                                         { return newlines(candidate) == newlines(previous->result); });
                     if (newlines(text) != newlines(previous->result))
                     {
+                        reason = L"undo-verification-mismatch";
                         if (tx.valid())
                             chord(VK_RIGHT);
                         return;
@@ -738,10 +845,11 @@ void App::transform(int command, int snippet)
                         tx.copyRange(recent.keys.size(), recent.keys, [&](const std::wstring &candidate)
                                      { return recent.match(candidate, available, physicalLayout()) >= 0; });
                     hint = recent.match(text, available, physicalLayout());
-                    log(L"Recent verification copied=" + std::to_wstring(text.size()) + L" keys=" +
+                    diagnosticEvent(L"Recent verification copied=" + std::to_wstring(text.size()) + L" keys=" +
                         std::to_wstring(recent.keys.size()) + L" match=" + std::to_wstring(hint));
                     if (hint < 0)
                     {
+                        reason = text.empty() ? L"recent-copy-empty" : L"recent-verification-mismatch";
                         if (tx.valid())
                             chord(VK_RIGHT);
                         return;
@@ -751,11 +859,13 @@ void App::transform(int command, int snippet)
                 else if (config.recent && previous && previous->window == target &&
                          previous->version == version)
                 {
+                    expected = previous->result;
                     text = tx.copyRange(caretSteps(previous->result), previous->result,
                                         [&](const std::wstring &candidate)
                                         { return newlines(candidate) == newlines(previous->result); });
                     if (newlines(text) != newlines(previous->result))
                     {
+                        reason = L"previous-result-verification-mismatch";
                         if (tx.valid())
                             chord(VK_RIGHT);
                         return;
@@ -765,10 +875,12 @@ void App::transform(int command, int snippet)
                 }
                 else
                     text = tx.copy();
+                reason = L"context-changed-after-copy";
                 if (!tx.valid())
                     return;
                 if (text.empty())
                 {
+                    reason = L"copy-empty";
                     if (to >= 0 && config.switchLayout)
                         switchWindowLayout(target, available[to].handle, valid);
                     return;
@@ -790,6 +902,7 @@ void App::transform(int command, int snippet)
                                         cycle.push_back(i);
                             if (cycle.size() < 2)
                             {
+                                reason = L"cycle-has-fewer-than-two-layouts";
                                 if (automatic && tx.valid())
                                     chord(VK_RIGHT);
                                 return;
@@ -804,12 +917,20 @@ void App::transform(int command, int snippet)
                     }
                 }
                 bool sent = false;
-                log(L"Conversion source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
+                diagnosticEvent(L"Conversion source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
                     L" changed=" + std::to_wstring(result != text));
                 if (result != text)
                     sent = tx.paste(textClip(result));
                 else if (automatic && tx.valid())
                     chord(VK_RIGHT);
+                reason = result == text ? L"conversion-unchanged" :
+                         sent ? L"paste-sent-unverified" : L"paste-cancelled";
+                if (result == text &&
+                    (std::none_of(text.begin(), text.end(), letter) ||
+                     (command >= Direct && detect(text, available, hint) == to)))
+                    reason = L"unchanged-expected";
+                if (sent && !tx.valid())
+                    reason = L"context-changed-after-paste";
                 if (sent && command == Undo && previous && previous->autoCorrected)
                     autoCorrector.reject(previous->original, config);
                 if (tx.valid() && (sent || automatic))
@@ -835,18 +956,22 @@ void App::transform(int command, int snippet)
                 if (to >= 0 && config.switchLayout && tx.valid() && (sent || result == text))
                 {
                     bool switched = switchWindowLayout(target, available[to].handle, valid);
-                    log(L"Layout switch confirmed=" + std::to_wstring(switched));
+                    diagnosticEvent(L"Layout switch confirmed=" + std::to_wstring(switched));
+                    if (!switched)
+                        reason += L";layout-switch-failed";
                 }
-                log(L"Text operation completed in " + std::to_wstring(GetTickCount64() - start) + L" ms");
+                diagnosticEvent(L"Text operation completed in " + std::to_wstring(GetTickCount64() - start) + L" ms");
             }
             catch (const std::exception &e)
             {
+                reason = L"exception:" + wide(e.what());
                 report(wide(e.what()));
             }
         });
 }
 void App::pasteEntry(std::wstring id, bool plain)
 {
+    if (installingUpdate) return;
     if (!history || busy.exchange(true))
         return;
     HWND target = pasteTarget;
@@ -984,6 +1109,10 @@ void App::trayMenu()
     AppendMenuW(pause, MF_STRING, 23, L"Until restart");
     AppendMenuW(menu, MF_POPUP, (UINT_PTR)pause, L"Pause clipboard history");
     AppendMenuW(menu, MF_STRING, 15, L"Open data folder");
+    AppendMenuW(menu, MF_STRING, 18, L"View log…");
+    AppendMenuW(menu, MF_STRING | (updateRunning ? MF_GRAYED : 0), 19,
+                updateRunning ? L"Update (checking / preparing…)" :
+                availableUpdate.empty() ? L"Update" : L"Update (new version available)");
     AppendMenuW(menu, MF_SEPARATOR, 0, nullptr);
     AppendMenuW(menu, MF_STRING, 16, L"About KSwitcher");
     AppendMenuW(menu, MF_STRING, 17, L"Exit");
@@ -1022,14 +1151,20 @@ void App::trayMenu()
             break;
         case 16:
             MessageBoxW(window,
-                        L"KSwitcher 0.1.0\nNative C++ / Win32 keyboard and clipboard utility\n\nBased on "
+                        (std::wstring(L"KSwitcher ") + AppVersion + L"\nNative C++ / Win32 keyboard and clipboard utility\n\nBased on "
                         L"Typlo by bitcodepro. MIT license.\nHistory is encrypted for your Windows "
-                        L"account.\nNo .NET, WebView or graphics framework.",
+                        L"account.\nNo .NET, WebView or graphics framework.").c_str(),
                         L"About KSwitcher", MB_OK);
             break;
         case 17:
             PostMessageW(window, WM_CLOSE, 0, 0);
             break;
+        case 18:
+            showLogs(*this);
+            break;
+        case 19:
+            checkUpdate(true);
+            break;
         case 20:
             pauseUntil = 0;
             break;
@@ -1049,6 +1184,32 @@ void App::trayMenu()
         report(wide(e.what()));
     }
 }
+void App::checkUpdate(bool interactive, bool install, const std::wstring &version)
+{
+    if (updateRunning) return;
+    if (install && FindWindowW(L"KSwitcher.Config", nullptr))
+    {
+        report(L"Close the configurator before installing an update.");
+        return;
+    }
+    if (install && busy)
+    {
+        report(L"Wait for the current text operation to finish, then select Update again.");
+        return;
+    }
+    if (updateWorker.joinable()) updateWorker.join();
+    updateRunning = true;
+    installingUpdate = install;
+    updateWorker = std::thread([this, interactive, install, version]
+    {
+        auto result = std::make_unique<UpdateResult>();
+        try { *result = runUpdate(install, version); }
+        catch (const std::exception &e) { result->state = L"error"; result->error = wide(e.what()); }
+        result->interactive = interactive;
+        result->install = install;
+        if (PostMessageW(window, UpdateMessage, 0, reinterpret_cast<LPARAM>(result.get()))) result.release();
+    });
+}
 LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
 {
     auto *app = current;
@@ -1061,6 +1222,50 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
     }
     switch (msg)
     {
+    case UpdateMessage:
+    {
+        std::unique_ptr<UpdateResult> result(reinterpret_cast<UpdateResult *>(lp));
+        if (app->updateWorker.joinable()) app->updateWorker.join();
+        app->updateRunning = false;
+        app->installingUpdate = false;
+        if (result->state == L"prepared")
+        {
+            // The helper has verified and staged the package; it waits for process exit.
+            DestroyWindow(hwnd);
+        }
+        else if (result->state == L"available")
+        {
+            app->availableUpdate = result->version;
+            if (result->interactive)
+            {
+                auto prompt = L"Install KSwitcher " + result->version +
+                    L"?\n\nThe program will close and restart. Settings, history and existing dictionaries are preserved.";
+                if (MessageBoxW(hwnd, prompt.c_str(), L"KSwitcher Update", MB_YESNO | MB_ICONQUESTION) == IDYES)
+                    app->checkUpdate(true, true, result->version);
+            }
+            else
+            {
+                NOTIFYICONDATAW icon{sizeof(icon)};
+                icon.hWnd = hwnd; icon.uID = 1; icon.uFlags = NIF_INFO; icon.dwInfoFlags = NIIF_INFO;
+                wcscpy_s(icon.szInfoTitle, L"KSwitcher update available");
+                auto text = result->version + L" is available. Select Update in the tray menu to install.";
+                wcsncpy_s(icon.szInfo, text.c_str(), _TRUNCATE);
+                Shell_NotifyIconW(NIM_MODIFY, &icon);
+            }
+        }
+        else if (result->state == L"current")
+        {
+            app->availableUpdate.clear();
+            if (result->interactive)
+                MessageBoxW(hwnd, (std::wstring(L"No newer stable release is available.\nInstalled version: ") + AppVersion).c_str(),
+                            L"KSwitcher Update", MB_OK | MB_ICONINFORMATION);
+        }
+        else if (result->interactive)
+            MessageBoxW(hwnd, (L"Update failed.\n\n" + result->error).c_str(), L"KSwitcher Update", MB_OK | MB_ICONERROR);
+        else
+            diagnosticEvent(L"Startup update check failed: " + result->error);
+        return 0;
+    }
     case WM_HOTKEY:
         app->dispatch((int)wp);
         return 0;
@@ -1078,10 +1283,12 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
         app->captureHistory();
         return 0;
     case AutoCorrectMessage:
+        if (app->installingUpdate) return 0;
         app->pendingAutoVersion = (uint64_t)wp;
         SetTimer(hwnd, 3, 250, nullptr);
         return 0;
     case SnippetMessage:
+        if (app->installingUpdate) return 0;
         app->transform(0, (int)wp);
         return 0;
     case HistoryMessage:
@@ -1104,6 +1311,11 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
     case WM_COPYDATA:
     {
         auto *data = (COPYDATASTRUCT *)lp;
+        if (data && data->dwData >= ConfigRead && data->dwData < ConfigReply)
+        {
+            if (app->installingUpdate) return FALSE;
+            return configurationRequest(*app, (HWND)wp, *data);
+        }
         if (data && data->dwData == 1 && data->cbData == sizeof(int))
         {
             int cmd;
@@ -1113,6 +1325,12 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
         return TRUE;
     }
     case WM_TIMER:
+        if (wp == 5)
+        {
+            KillTimer(hwnd, 5);
+            app->checkUpdate(false);
+            return 0;
+        }
         if (wp == 4)
         {
             if (GetAsyncKeyState(VK_LBUTTON) & 0x8000)
@@ -1124,7 +1342,7 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
         if (wp == 3)
         {
             KillTimer(hwnd, 3);
-            if (app->settings.autoCorrect && app->inputVersion.load() == app->pendingAutoVersion)
+            if (!app->installingUpdate && app->settings.autoCorrect && app->inputVersion.load() == app->pendingAutoVersion)
                 app->transform(AutoCorrect);
             return 0;
         }
@@ -1141,6 +1359,11 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
         }
         return 0;
     case WM_CLOSE:
+        if (app->updateRunning)
+        {
+            app->report(L"Wait for the update check or preparation to finish before exiting.");
+            return 0;
+        }
         if (app->busy)
         {
             app->report(L"Wait for the current text operation to finish before exiting.");
@@ -1149,6 +1372,9 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
         DestroyWindow(hwnd);
         return 0;
     case WM_DESTROY:
+        if (auto config = FindWindowW(L"KSwitcher.Config", nullptr);
+            config && configurationPeer(config, L"KSwitcher.Config.exe"))
+            PostMessageW(config, WM_CLOSE, 0, 0);
         PostQuitMessage(0);
         return 0;
     default:
@@ -1210,6 +1436,10 @@ int App::execute()
         report(registrationWarning);
     if (smoke)
         SetTimer(window, 2, 10000, nullptr);
+    else
+        SetTimer(window, 5, 5000, nullptr);
+    if (keyboardHook && mouseHook)
+        confirmUpdatedStartup(updateStartupEvent);
     if (startCommand)
         PostMessageW(window, WM_HOTKEY, startCommand, 0);
     MSG msg;
@@ -1225,6 +1455,8 @@ int App::execute()
             continue;
         if (snippetsWindow && IsDialogMessageW(snippetsWindow, &msg))
             continue;
+        if (logWindow && IsDialogMessageW(logWindow, &msg))
+            continue;
         TranslateMessage(&msg);
         DispatchMessageW(&msg);
     }

src/app.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "autocorrect.h"
 #include "storage.h"
+#include "update.h"
 #include <atomic>
 #include <condition_variable>
 #include <deque>
@@ -42,12 +43,15 @@ class App
     std::atomic<ULONGLONG> pauseUntil{0};
     HWND pasteTarget{};
     HWND hotkeyCapture{};
+    DWORD hotkeyCaptureProcess{};
+    HWND logWindow{};
     std::mutex stateMutex;
     Run run;
     std::optional<LastTransform> last;
     std::wstring registrationWarning;
     bool smoke{};
     int startCommand{};
+    std::wstring updateStartupEvent;
     App(HINSTANCE, bool = false, const std::filesystem::path &dataRoot = {});
     ~App();
     int execute();
@@ -63,20 +67,32 @@ class App
     bool registerHotkeys(const Settings &, bool rollback = false);
     void applySettings(const Settings &);
     void reloadLayouts();
+    void clearHistory();
+    void setHotkeyCapture(HWND);
     bool isHotkey(DWORD, UINT);
-    void keyboard(const KBDLLHOOKSTRUCT &);
+    void keyboard(const KBDLLHOOKSTRUCT &, UINT modifiers);
+    bool handleKeyboard(const KBDLLHOOKSTRUCT &, bool down, UINT modifiers);
     void resetInput();
+    void checkUpdate(bool interactive, bool install = false, const std::wstring &version = {});
     static App *current;
 
   private:
+    friend struct InputRegressionAccess;
     HHOOK keyboardHook{}, mouseHook{};
     std::mutex jobsMutex;
     std::condition_variable jobsReady;
     std::deque<std::function<void()>> jobs;
     std::thread worker;
+    std::thread updateWorker;
+    bool updateRunning{}, installingUpdate{};
+    std::wstring availableUpdate;
     bool stop{};
     UINT taskbarCreated{};
     uint64_t pendingAutoVersion{};
+    uint64_t transformAttempt{}, previousAttemptVersion{};
+    ULONGLONG previousAttemptAt{};
+    HWND previousAttemptWindow{};
+    int previousAttemptCommand{}, repeatAttempts{};
     std::vector<std::pair<int, Hotkey>> hookBindings;
     HotkeyHook hotkeyHook;
     static LRESULT CALLBACK windowProc(HWND, UINT, WPARAM, LPARAM);
@@ -85,7 +101,8 @@ class App
 };
 void showHistory(App &);
 void refreshHistory(App &);
-void showSettings(App &);
+void showSettings(App &, bool visible = true);
+void showLogs(App &);
 void showSnippets(App &);
 void showShortcuts(App &);
 void showEntry(App &, const std::wstring &);

src/config_main.cpp

@@ -0,0 +1,205 @@
+#include "configuration.h"
+#include <commctrl.h>
+#include <cstring>
+
+namespace ks
+{
+App *App::current = nullptr;
+namespace
+{
+HWND service{};
+Bytes response;
+bool replied{};
+Bytes request(App &app, ULONG_PTR command, const Bytes &payload = {})
+{
+    if (!service || !configurationPeer(service, L"KSwitcher.exe"))
+        throw std::runtime_error("KSwitcher has stopped. Close and reopen the configurator.");
+    if (payload.size() > ConfigLimit) throw std::runtime_error("Settings are too large.");
+    response.clear(); replied = false;
+    COPYDATASTRUCT message{command, (DWORD)payload.size(), const_cast<unsigned char *>(payload.data())};
+    DWORD_PTR result{};
+    SetLastError(ERROR_SUCCESS);
+    if (!SendMessageTimeoutW(service, WM_COPYDATA, (WPARAM)app.window, (LPARAM)&message,
+                             SMTO_ABORTIFHUNG | SMTO_ERRORONEXIT, 15000, &result) || !replied)
+    {
+        if (GetLastError() == ERROR_ACCESS_DENIED)
+            throw std::runtime_error("Open Settings from the KSwitcher tray menu so both processes use the same privileges.");
+        throw std::runtime_error("KSwitcher did not respond. The operation may still finish; reopen Settings to check.");
+    }
+    if (result != 1)
+        throw std::runtime_error(response.empty() ? "KSwitcher rejected the request." :
+                                 std::string(response.begin(), response.end()));
+    return response;
+}
+LRESULT CALLBACK controller(HWND window, UINT message, WPARAM wp, LPARAM lp)
+{
+    auto *app = App::current;
+    if (!app) return DefWindowProcW(window, message, wp, lp);
+    if (message == WM_COPYDATA)
+    {
+        auto *data = reinterpret_cast<COPYDATASTRUCT *>(lp);
+        if ((HWND)wp == service && data && data->dwData == ConfigReply && data->cbData <= ConfigLimit &&
+            (!data->cbData || data->lpData))
+        {
+            response.clear();
+            if (data->cbData)
+            {
+                auto first = static_cast<const unsigned char *>(data->lpData);
+                response.assign(first, first + data->cbData);
+            }
+            replied = true;
+            return TRUE;
+        }
+        return FALSE;
+    }
+    if (message == WM_APP + 20)
+    {
+        try
+        {
+            if (wp == 21) showSnippets(*app);
+            else showSettings(*app);
+        }
+        catch (const std::exception &e)
+        {
+            MessageBoxW(app->settingsWindow, wide(e.what()).c_str(), L"KSwitcher configurator", MB_OK | MB_ICONERROR);
+        }
+        return 0;
+    }
+    if (message == WM_CLOSE)
+    {
+        if (app->settingsWindow) DestroyWindow(app->settingsWindow);
+        if (app->snippetsWindow) DestroyWindow(app->snippetsWindow);
+        PostQuitMessage(0);
+        return 0;
+    }
+    return DefWindowProcW(window, message, wp, lp);
+}
+}
+// The configurator owns no history store, dictionaries, worker or input hooks.
+// All mutations are validated and committed by the resident process.
+App::App(HINSTANCE h, bool, const std::filesystem::path &) : instance(h)
+{
+    current = this;
+    layouts = readLayouts();
+}
+App::~App()
+{
+    if (settingsWindow) DestroyWindow(settingsWindow);
+    if (snippetsWindow) DestroyWindow(snippetsWindow);
+    if (window) DestroyWindow(window);
+    current = nullptr;
+}
+void App::applySettings(const Settings &next)
+{
+    validateSettings(next);
+    auto before = encodeSettings(settings), after = encodeSettings(next);
+    DWORD length = (DWORD)before.size();
+    Bytes payload(sizeof(length));
+    memcpy(payload.data(), &length, sizeof(length));
+    payload.insert(payload.end(), before.begin(), before.end());
+    payload.insert(payload.end(), after.begin(), after.end());
+    settings = decodeSettings(request(*this, ConfigSave, payload), layouts);
+}
+void App::reloadLayouts()
+{
+    auto bytes = request(*this, ConfigLayouts);
+    layouts = readLayouts();
+    settings = decodeSettings(bytes, layouts);
+}
+void App::clearHistory() { request(*this, ConfigClearHistory); }
+void App::setHotkeyCapture(HWND field)
+{
+    hotkeyCapture = field;
+    Bytes payload(sizeof(field));
+    memcpy(payload.data(), &field, sizeof(field));
+    // Focus notifications must not let an exception escape a window callback.
+    try { request(*this, ConfigCapture, payload); }
+    catch (const std::exception &e)
+    {
+        hotkeyCapture = nullptr;
+        if (field) MessageBoxW(settingsWindow, wide(e.what()).c_str(), L"Shortcut capture unavailable", MB_OK | MB_ICONWARNING);
+    }
+}
+void showLogs(App &app) { request(app, ConfigLogs); }
+
+int runConfigurator(HINSTANCE instance, bool snippets)
+{
+    HANDLE singleton = CreateMutexW(nullptr, TRUE, L"Local\\KSwitcher.Config.Singleton");
+    if (!singleton) throw std::runtime_error("Cannot create configurator instance lock.");
+    const bool existing = GetLastError() == ERROR_ALREADY_EXISTS;
+    struct Close { HANDLE handle; ~Close() { CloseHandle(handle); } } close{singleton};
+    if (existing)
+    {
+        HWND window{};
+        for (int i = 0; i < 100 && !window; ++i)
+        {
+            window = FindWindowW(L"KSwitcher.Config", nullptr);
+            if (!window) Sleep(50);
+        }
+        if (!window || !configurationPeer(window, L"KSwitcher.Config.exe"))
+            throw std::runtime_error("The configurator is starting or belongs to another installation. Try again shortly.");
+        DWORD pid{}; GetWindowThreadProcessId(window, &pid);
+        AllowSetForegroundWindow(pid);
+        PostMessageW(window, WM_APP + 20, snippets ? 21 : 20, 0);
+        return 0;
+    }
+    service = FindWindowW(L"KSwitcher.Main", L"KSwitcher");
+    if (!service)
+    {
+        auto path = std::filesystem::path(executable()).parent_path() / L"KSwitcher.exe";
+        auto command = L"\"" + path.wstring() + L"\"";
+        STARTUPINFOW startup{sizeof(startup)}; PROCESS_INFORMATION process{};
+        if (!CreateProcessW(path.c_str(), command.data(), nullptr, nullptr, FALSE, 0, nullptr,
+                            path.parent_path().c_str(), &startup, &process))
+            throw std::runtime_error("Cannot start KSwitcher beside the configurator.");
+        CloseHandle(process.hThread); CloseHandle(process.hProcess);
+        for (int i = 0; i < 100 && !service; ++i)
+        {
+            Sleep(50); service = FindWindowW(L"KSwitcher.Main", L"KSwitcher");
+        }
+    }
+    if (!configurationPeer(service, L"KSwitcher.exe"))
+        throw std::runtime_error("Run the configurator from the active KSwitcher installation.");
+    INITCOMMONCONTROLSEX controls{sizeof(controls), ICC_STANDARD_CLASSES};
+    InitCommonControlsEx(&controls);
+    App app(instance);
+    WNDCLASSW cls{}; cls.hInstance = instance; cls.lpfnWndProc = controller; cls.lpszClassName = L"KSwitcher.Config";
+    RegisterClassW(&cls);
+    app.window = CreateWindowExW(WS_EX_TOOLWINDOW, cls.lpszClassName, L"KSwitcher configurator", WS_POPUP,
+                                 0, 0, 0, 0, nullptr, nullptr, instance, nullptr);
+    if (!app.window) throw std::runtime_error("Cannot create configurator window.");
+    app.settings = decodeSettings(request(app, ConfigRead), app.layouts);
+    if (snippets) showSnippets(app); else showSettings(app);
+    MSG message;
+    while ((app.settingsWindow || app.snippetsWindow) && GetMessageW(&message, nullptr, 0, 0) > 0)
+    {
+        if (app.settingsWindow && !IsWindowEnabled(app.settingsWindow))
+        {
+            HWND popup = GetLastActivePopup(app.settingsWindow);
+            if (popup != app.settingsWindow && IsDialogMessageW(popup, &message)) continue;
+        }
+        if (app.settingsWindow && IsDialogMessageW(app.settingsWindow, &message)) continue;
+        if (app.snippetsWindow && IsDialogMessageW(app.snippetsWindow, &message)) continue;
+        TranslateMessage(&message); DispatchMessageW(&message);
+    }
+    return 0;
+}
+}
+int WINAPI wWinMain(HINSTANCE instance, HINSTANCE, PWSTR, int)
+{
+    CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
+    int result = 1;
+    try
+    {
+        int count{}; auto args = CommandLineToArgvW(GetCommandLineW(), &count);
+        bool snippets = count > 1 && std::wstring(args[1]) == L"--snippets";
+        LocalFree(args);
+        result = ks::runConfigurator(instance, snippets);
+    }
+    catch (const std::exception &e)
+    {
+        MessageBoxW(nullptr, ks::wide(e.what()).c_str(), L"KSwitcher configurator", MB_OK | MB_ICONERROR);
+    }
+    CoUninitialize();
+    return result;
+}

src/configuration.cpp

@@ -0,0 +1,98 @@
+#include "configuration.h"
+#include <cstring>
+namespace ks
+{
+bool configurationPeer(HWND window, const wchar_t *filename)
+{
+    DWORD pid{};
+    GetWindowThreadProcessId(window, &pid);
+    HANDLE process = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, pid);
+    if (!process) return false;
+    wchar_t path[32768]; DWORD count = std::size(path);
+    bool ok = QueryFullProcessImageNameW(process, 0, path, &count) != 0;
+    CloseHandle(process);
+    auto expected = std::filesystem::path(executable()).parent_path() / filename;
+    return ok && _wcsicmp(path, expected.c_str()) == 0;
+}
+void launchConfiguration(App &app, bool snippets)
+{
+    auto path = std::filesystem::path(executable()).parent_path() / L"KSwitcher.Config.exe";
+    if (!std::filesystem::exists(path))
+        throw std::runtime_error("KSwitcher.Config.exe is missing. Extract the complete application package.");
+    auto command = L"\"" + path.wstring() + L"\"" + (snippets ? L" --snippets" : L"");
+    STARTUPINFOW startup{sizeof(startup)};
+    PROCESS_INFORMATION process{};
+    if (!CreateProcessW(path.c_str(), command.data(), nullptr, nullptr, FALSE, 0, nullptr,
+                        path.parent_path().c_str(), &startup, &process))
+        throw std::runtime_error(utf8(lastError(L"Cannot start configurator")));
+    AllowSetForegroundWindow(process.dwProcessId);
+    CloseHandle(process.hThread);
+    CloseHandle(process.hProcess);
+    (void)app;
+}
+LRESULT configurationRequest(App &app, HWND sender, const COPYDATASTRUCT &message)
+{
+    if (!configurationPeer(sender, L"KSwitcher.Config.exe") || message.cbData > ConfigLimit ||
+        (message.cbData && !message.lpData)) return FALSE;
+    Bytes reply;
+    bool ok = false;
+    try
+    {
+        switch (message.dwData)
+        {
+        case ConfigSave:
+        {
+            if (app.busy) throw std::runtime_error("Wait for the current text operation to finish.");
+            if (message.cbData < sizeof(DWORD)) throw std::runtime_error("Invalid settings request.");
+            DWORD length{};
+            memcpy(&length, message.lpData, sizeof(length));
+            if (length > message.cbData - sizeof(length)) throw std::runtime_error("Invalid settings snapshot.");
+            auto begin = static_cast<const unsigned char *>(message.lpData) + sizeof(length);
+            if (Bytes(begin, begin + length) != encodeSettings(app.settings))
+                throw std::runtime_error("Settings changed in KSwitcher. Close and reopen the configurator before saving.");
+            Bytes next(begin + length, static_cast<const unsigned char *>(message.lpData) + message.cbData);
+            if (next.empty()) throw std::runtime_error("Empty settings request.");
+            app.applySettings(decodeSettings(next, app.layouts));
+            reply = encodeSettings(app.settings);
+            break;
+        }
+        case ConfigLayouts:
+            if (app.busy) throw std::runtime_error("Wait for the current text operation to finish.");
+            app.reloadLayouts();
+            [[fallthrough]];
+        case ConfigRead:
+            reply = encodeSettings(app.settings);
+            break;
+        case ConfigClearHistory:
+            app.clearHistory();
+            break;
+        case ConfigCapture:
+        {
+            if (message.cbData != sizeof(HWND)) throw std::runtime_error("Invalid shortcut field.");
+            HWND field{}; memcpy(&field, message.lpData, sizeof(field));
+            DWORD fieldPid{}, senderPid{};
+            GetWindowThreadProcessId(field, &fieldPid);
+            GetWindowThreadProcessId(sender, &senderPid);
+            if (field && fieldPid != senderPid) throw std::runtime_error("Invalid shortcut field owner.");
+            app.setHotkeyCapture(field);
+            break;
+        }
+        case ConfigLogs:
+            PostMessageW(app.window, WM_HOTKEY, 22, 0);
+            break;
+        default: return FALSE;
+        }
+        ok = true;
+    }
+    catch (const std::exception &error)
+    {
+        std::string text = error.what();
+        reply.assign(text.begin(), text.end());
+    }
+    COPYDATASTRUCT response{ConfigReply, (DWORD)reply.size(), reply.data()};
+    DWORD_PTR received{};
+    if (!SendMessageTimeoutW(sender, WM_COPYDATA, (WPARAM)app.window, (LPARAM)&response,
+                             SMTO_ABORTIFHUNG, 2000, &received)) return FALSE;
+    return ok ? 1 : 2;
+}
+}

src/configuration.h

@@ -0,0 +1,13 @@
+#pragma once
+#include "app.h"
+namespace ks
+{
+inline constexpr ULONG_PTR ConfigRead = 0x4b530100, ConfigSave = ConfigRead + 1,
+    ConfigLayouts = ConfigRead + 2, ConfigClearHistory = ConfigRead + 3,
+    ConfigCapture = ConfigRead + 4, ConfigLogs = ConfigRead + 5,
+    ConfigReply = ConfigRead + 6;
+inline constexpr size_t ConfigLimit = 8 * 1024 * 1024;
+bool configurationPeer(HWND, const wchar_t *filename);
+void launchConfiguration(App &, bool snippets = false);
+LRESULT configurationRequest(App &, HWND sender, const COPYDATASTRUCT &);
+}

src/core.h

@@ -47,6 +47,7 @@ struct Settings
     bool recent = true, switchLayout = true, history = true, autostart = false, awake = false;
     bool elevatedAutostart = false;
     bool autoCorrect = false;
+    bool writeLog = true;
     int autoMaxRank = 0;
     int autoMinLength = 3;
     std::wstring autoPrefixChars = L"([{«“‘\"";

src/main.cpp

@@ -67,7 +67,9 @@ int WINAPI wWinMain(HINSTANCE instance, HINSTANCE, PWSTR, int)
     try
     {
         ks::App app(instance, arg == L"--smoke-test");
-        if (!arg.empty() && arg != L"--smoke-test")
+        if (arg.starts_with(L"--update-ready-event="))
+            app.updateStartupEvent = arg.substr(std::wstring(L"--update-ready-event=").size());
+        else if (!arg.empty() && arg != L"--smoke-test")
             app.startCommand = cmd;
         result = app.execute();
     }

src/platform.cpp

@@ -347,15 +347,30 @@ size_t Clip::size() const
         n += f.data.size();
     return n;
 }
+ULONG_PTR inputMarker()
+{
+    static const char marker{};
+    return reinterpret_cast<ULONG_PTR>(&marker);
+}
+bool ownKeyboardInput(const KBDLLHOOKSTRUCT &key)
+{
+    return (key.flags & LLKHF_INJECTED) && key.dwExtraInfo == inputMarker();
+}
+INPUT keyboardInput(WORD key, DWORD flags)
+{
+    INPUT input{};
+    input.type = INPUT_KEYBOARD;
+    input.ki.wVk = key;
+    input.ki.dwFlags = flags;
+    input.ki.dwExtraInfo = inputMarker();
+    return input;
+}
 bool chord(WORD key, UINT mods)
 {
     std::vector<INPUT> inputs;
     auto add = [&](WORD k, bool up)
     {
-        INPUT i{};
-        i.type = INPUT_KEYBOARD;
-        i.ki.wVk = k;
-        i.ki.dwFlags = up ? KEYEVENTF_KEYUP : 0;
+        INPUT i = keyboardInput(k, up ? KEYEVENTF_KEYUP : 0);
         if (k == VK_LEFT || k == VK_RIGHT || k == VK_INSERT)
             i.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;
         inputs.push_back(i);
@@ -406,10 +421,7 @@ bool selectPrevious(size_t count, const std::function<bool()> &valid)
         std::vector<INPUT> inputs;
         auto add = [&](WORD key, DWORD flags)
         {
-            INPUT i{};
-            i.type = INPUT_KEYBOARD;
-            i.ki.wVk = key;
-            i.ki.dwFlags = flags;
+            INPUT i = keyboardInput(key, flags);
             inputs.push_back(i);
         };
         add(VK_SHIFT, 0);
@@ -437,10 +449,7 @@ void releaseModifiers()
     for (int k : {VK_LCONTROL, VK_RCONTROL, VK_LMENU, VK_RMENU, VK_LSHIFT, VK_RSHIFT, VK_LWIN, VK_RWIN})
         if (GetAsyncKeyState(k) & 0x8000)
         {
-            INPUT i{};
-            i.type = INPUT_KEYBOARD;
-            i.ki.wVk = (WORD)k;
-            i.ki.dwFlags = KEYEVENTF_KEYUP;
+            INPUT i = keyboardInput((WORD)k, KEYEVENTF_KEYUP);
             inputs.push_back(i);
         }
     if (!inputs.empty())
@@ -527,16 +536,112 @@ std::wstring lastError(const std::wstring &context)
 {
     return context + L" (Windows error " + std::to_wstring(GetLastError()) + L")";
 }
+std::wstring diagnosticText(const std::wstring &text)
+{
+    // Escape UTF-16 code units so invisible characters and malformed surrogate pairs
+    // can be reproduced without introducing fake log lines. Bound large selections.
+    std::wstring out = L"\"";
+    constexpr wchar_t hex[] = L"0123456789abcdef";
+    const auto count = std::min<size_t>(text.size(), 512);
+    for (size_t i = 0; i < count; ++i)
+    {
+        auto c = static_cast<unsigned short>(text[i]);
+        if (c == L'"' || c == L'\\')
+        {
+            out += L'\\';
+            out += c;
+        }
+        else if (c < 32 || c >= 127)
+        {
+            out += L"\\u";
+            for (int shift = 12; shift >= 0; shift -= 4)
+                out += hex[(c >> shift) & 15];
+        }
+        else
+            out += c;
+    }
+    return out + L"\" units=" + std::to_wstring(text.size()) +
+           L" truncated=" + std::to_wstring(count != text.size());
+}
+namespace
+{
+std::recursive_mutex logGate;
+bool loggingEnabled = false;
+DiagnosticBuffer diagnosticBuffer;
+}
+std::wstring DiagnosticBuffer::record(const std::wstring &message, bool problem, ULONGLONG now)
+{
+    while (!entries.empty() && (entries.size() >= 40 || now - entries.front().first > 30000))
+        entries.pop_front();
+    entries.emplace_back(now, message);
+    if (!problem)
+        return {};
+    std::wstring out = L"Diagnostic incident (preceding context, up to 30 seconds):";
+    for (const auto &[at, entry] : entries)
+        out += L"\n  ageMs=" + std::to_wstring(now - at) + L" " + entry;
+    entries.clear();
+    return out;
+}
+void setLoggingEnabled(bool enabled)
+{
+    std::lock_guard lock(logGate);
+    loggingEnabled = enabled;
+    if (!enabled)
+        diagnosticBuffer.clear();
+}
+std::wstring readDiagnosticLog(bool previous)
+{
+    std::lock_guard lock(logGate);
+    auto path = dataDirectory() / (previous ? L"kswitcher.log.1" : L"kswitcher.log");
+    if (!std::filesystem::exists(path))
+        return previous ? L"No previous log is available yet." : L"No log yet. Entries will appear when a problem is detected.";
+    auto bytes = readFile(path, 2 * 1024 * 1024);
+    auto text = wide(std::string(bytes.begin(), bytes.end()));
+    std::wstring display;
+    for (size_t i = 0; i < text.size(); ++i)
+    {
+        if (text[i] == L'\n' && (i == 0 || text[i - 1] != L'\r'))
+            display += L'\r';
+        display += text[i];
+    }
+    return display.empty() ? L"The log is empty." : display;
+}
+void clearDiagnosticLog(bool previous)
+{
+    // Serialize clearing with writes and rotation. Never delete the other log.
+    std::lock_guard lock(logGate);
+    auto path = dataDirectory() / (previous ? L"kswitcher.log.1" : L"kswitcher.log");
+    std::filesystem::remove(path);
+    if (!previous)
+        diagnosticBuffer.clear();
+}
+void diagnosticEvent(const std::wstring &message, bool problem)
+{
+    std::lock_guard lock(logGate);
+    if (!loggingEnabled)
+        return;
+    auto incident = diagnosticBuffer.record(message, problem, GetTickCount64());
+    if (!incident.empty())
+        log(incident);
+}
 void log(const std::wstring &message)
 {
-    static std::mutex gate;
-    std::lock_guard lock(gate);
+    std::lock_guard lock(logGate);
+    if (!loggingEnabled)
+        return;
     try
     {
         auto path = dataDirectory() / L"kswitcher.log";
         std::error_code ec;
-        if (std::filesystem::file_size(path, ec) > 256 * 1024)
-            std::filesystem::remove(path, ec);
+        auto size = std::filesystem::file_size(path, ec);
+        if (!ec && size > 256 * 1024)
+        {
+            auto previous = path;
+            previous += L".1";
+            std::filesystem::remove(previous, ec);
+            ec.clear();
+            std::filesystem::rename(path, previous, ec);
+        }
         std::ofstream f(path, std::ios::app);
         SYSTEMTIME t;
         GetLocalTime(&t);

src/platform.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "core.h"
 #include <filesystem>
+#include <deque>
 #include <objbase.h>
 #include <span>
 #include <stdexcept>
@@ -35,6 +36,10 @@ Clip readClipboard(HWND, size_t limit = 32 * 1024 * 1024);
 DWORD writeClipboard(HWND, const Clip &);
 Clip textClip(const std::wstring &);
 bool chord(WORD key, UINT modifiers = 0);
+// Process-local marker, shared by every KSwitcher input producer (not an authentication token).
+ULONG_PTR inputMarker();
+bool ownKeyboardInput(const KBDLLHOOKSTRUCT &);
+INPUT keyboardInput(WORD key, DWORD flags = 0);
 bool needsSelectionDelay(HWND);
 bool selectPrevious(size_t count, const std::function<bool()> &valid);
 bool modifiersReleased();
@@ -50,4 +55,17 @@ void configureAutostart(int mode);
 std::wstring executable();
 std::wstring lastError(const std::wstring &context);
 void log(const std::wstring &message);
+std::wstring diagnosticText(const std::wstring &text);
+// A bounded, short-lived context. A problem drains it, so old incidents are not repeated.
+class DiagnosticBuffer
+{
+    std::deque<std::pair<ULONGLONG, std::wstring>> entries;
+  public:
+    std::wstring record(const std::wstring &message, bool problem, ULONGLONG now);
+    void clear() { entries.clear(); }
+};
+void setLoggingEnabled(bool enabled);
+void diagnosticEvent(const std::wstring &message, bool problem = false);
+std::wstring readDiagnosticLog(bool previous);
+void clearDiagnosticLog(bool previous);
 } // namespace ks

src/storage.cpp

@@ -102,6 +102,10 @@ void validateSettings(const Settings &s)
     }
 }
 Settings loadSettings(const std::filesystem::path &path, const std::vector<Layout> &layouts)
+{
+    return decodeSettings(std::filesystem::exists(path) ? readFile(path, 4 * 1024 * 1024) : Bytes{}, layouts);
+}
+Settings decodeSettings(const Bytes &bytes, const std::vector<Layout> &layouts)
 {
     Settings s;
     for (size_t i = 0; i < layouts.size(); ++i)
@@ -111,14 +115,15 @@ Settings loadSettings(const std::filesystem::path &path, const std::vector<Layou
         s.direct.push_back(i < 3 ? L"Ctrl+Alt+Shift+" + std::to_wstring(i + 1) : L"");
         s.directIds.push_back(layouts[i].id);
     }
-    if (!std::filesystem::exists(path))
+    if (bytes.empty())
         return s;
-    auto j = parse(readFile(path, 4 * 1024 * 1024));
+    auto j = parse(bytes);
     auto format = j.value("format", std::string());
     if (format != "kswitcher-settings" && format != "typlo-settings")
         throw std::runtime_error("Not a KSwitcher or Typlo settings file");
     s.recent = j.value("convertLastWord", true);
     s.switchLayout = j.value("switchSystemLayout", true);
+    s.writeLog = j.value("writeLog", true);
     s.history = j.value("historyEnabled", true);
     s.autostart = j.value("startWithSystem", false);
     s.elevatedAutostart = j.value("autostartAsAdministrator", false);
@@ -176,12 +181,17 @@ Settings loadSettings(const std::filesystem::path &path, const std::vector<Layou
     return s;
 }
 void saveSettings(const std::filesystem::path &path, const Settings &s)
+{
+    atomicWrite(path, encodeSettings(s));
+}
+Bytes encodeSettings(const Settings &s)
 {
     validateSettings(s);
     Json j = {{"format", "kswitcher-settings"},
               {"schemaVersion", 1},
               {"convertLastWord", s.recent},
               {"switchSystemLayout", s.switchLayout},
+              {"writeLog", s.writeLog},
               {"autostartAsAdministrator", s.elevatedAutostart},
               {"historyEnabled", s.history},
               {"startWithSystem", s.autostart},
@@ -219,7 +229,7 @@ void saveSettings(const std::filesystem::path &path, const Settings &s)
     j["excludedApps"] = Json::array();
     for (auto &name : s.excluded)
         j["excludedApps"].push_back(utf8(name));
-    atomicWrite(path, jsonBytes(j));
+    return jsonBytes(j);
 }
 Bytes encodeClip(const Clip &clip)
 {

src/storage.h

@@ -4,6 +4,8 @@
 namespace ks
 {
 Settings loadSettings(const std::filesystem::path &, const std::vector<Layout> &);
+Settings decodeSettings(const Bytes &, const std::vector<Layout> &);
+Bytes encodeSettings(const Settings &);
 void saveSettings(const std::filesystem::path &, const Settings &);
 void validateSettings(const Settings &);
 struct Entry

src/ui.cpp

@@ -1,7 +1,9 @@
 #include "../resources/resource.h"
 #include "app.h"
+#include "configuration.h"
 #include "ocr.h"
 #include "richtext.h"
+#include "ui_geometry.h"
 #include <algorithm>
 #include <commctrl.h>
 #include <commdlg.h>
@@ -26,6 +28,129 @@ HFONT font(HWND w)
                        OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, CLEARTYPE_QUALITY, DEFAULT_PITCH,
                        L"Segoe UI");
 }
+struct WindowLayout
+{
+    int width{}, height{}, x{}, y{};
+    bool scrolling{}, arranging{};
+    int wheelRemainder{}, horizontalWheelRemainder{};
+    std::vector<std::pair<HWND, RECT>> controls; // Original 96-DPI geometry; never rescale rounded pixels.
+};
+WindowLayout *windowLayoutState(HWND w)
+{
+    return reinterpret_cast<WindowLayout *>(GetPropW(w, L"WindowLayout"));
+}
+RECT workArea(RECT rect)
+{
+    MONITORINFO monitor{sizeof(monitor)};
+    GetMonitorInfoW(MonitorFromRect(&rect, MONITOR_DEFAULTTONEAREST), &monitor);
+    return monitor.rcWork;
+}
+void fitToMonitor(HWND w, RECT rect)
+{
+    rect = fitWindowRect(rect, workArea(rect));
+    SetWindowPos(w, nullptr, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,
+                 SWP_NOACTIVATE | SWP_NOZORDER);
+}
+void arrangeWindow(HWND w)
+{
+    auto *layout = windowLayoutState(w);
+    if (!layout || !layout->scrolling || layout->arranging) return;
+    layout->arranging = true;
+    // Showing either scrollbar can make the other necessary. Let the client size settle.
+    for (int pass = 0; pass < 3; ++pass)
+    {
+        RECT client{};
+        GetClientRect(w, &client);
+        SCROLLINFO horizontal{sizeof(horizontal), SIF_RANGE | SIF_PAGE | SIF_POS,
+                              0, scale(w, layout->width) - 1, (UINT)client.right, layout->x};
+        SCROLLINFO vertical{sizeof(vertical), SIF_RANGE | SIF_PAGE | SIF_POS,
+                            0, scale(w, layout->height) - 1, (UINT)client.bottom, layout->y};
+        layout->x = SetScrollInfo(w, SB_HORZ, &horizontal, TRUE);
+        layout->y = SetScrollInfo(w, SB_VERT, &vertical, TRUE);
+    }
+    for (const auto &[child, r] : layout->controls)
+        SetWindowPos(child, nullptr, scale(w, r.left) - layout->x, scale(w, r.top) - layout->y,
+                     scale(w, r.right - r.left), scale(w, r.bottom - r.top), SWP_NOACTIVATE | SWP_NOZORDER);
+    layout->arranging = false;
+    InvalidateRect(w, nullptr, TRUE);
+}
+void revealControl(HWND child)
+{
+    HWND parent = GetParent(child);
+    auto *layout = windowLayoutState(parent);
+    if (!layout || !layout->scrolling) return;
+    RECT r{}, client{};
+    GetWindowRect(child, &r);
+    MapWindowPoints(nullptr, parent, reinterpret_cast<POINT *>(&r), 2);
+    GetClientRect(parent, &client);
+    if (r.left < 0) layout->x += r.left;
+    else if (r.right > client.right) layout->x += r.right - client.right;
+    if (r.top < 0) layout->y += r.top;
+    else if (r.bottom > client.bottom) layout->y += r.bottom - client.bottom;
+    arrangeWindow(parent);
+}
+LRESULT CALLBACK scrollChildProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
+{
+    if (msg == WM_SETFOCUS) revealControl(w);
+    if (msg == WM_NCDESTROY) RemoveWindowSubclass(w, scrollChildProc, 2);
+    return DefSubclassProc(w, msg, wp, lp);
+}
+void resizeForDpi(HWND, WPARAM, LPARAM);
+LRESULT CALLBACK layoutProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
+{
+    auto *layout = windowLayoutState(w);
+    if (!layout) return DefSubclassProc(w, msg, wp, lp);
+    if (msg == WM_DPICHANGED)
+    {
+        resizeForDpi(w, wp, lp);
+        return 0;
+    }
+    if (msg == WM_SIZE) arrangeWindow(w);
+    if (msg == WM_DISPLAYCHANGE || msg == WM_SETTINGCHANGE || (msg == WM_SHOWWINDOW && wp))
+    {
+        RECT rect{};
+        GetWindowRect(w, &rect);
+        fitToMonitor(w, rect);
+        arrangeWindow(w);
+    }
+    if (layout->scrolling && (msg == WM_VSCROLL || msg == WM_HSCROLL))
+    {
+        bool vertical = msg == WM_VSCROLL;
+        SCROLLINFO info{sizeof(info), SIF_ALL};
+        GetScrollInfo(w, vertical ? SB_VERT : SB_HORZ, &info);
+        int &position = vertical ? layout->y : layout->x;
+        switch (LOWORD(wp))
+        {
+        case SB_LINEUP: position -= scale(w, 32); break;
+        case SB_LINEDOWN: position += scale(w, 32); break;
+        case SB_PAGEUP: position -= (int)info.nPage; break;
+        case SB_PAGEDOWN: position += (int)info.nPage; break;
+        case SB_TOP: position = 0; break;
+        case SB_BOTTOM: position = info.nMax; break;
+        case SB_THUMBTRACK: case SB_THUMBPOSITION: position = info.nTrackPos; break;
+        }
+        arrangeWindow(w);
+        return 0;
+    }
+    if (layout->scrolling && (msg == WM_MOUSEWHEEL || msg == WM_MOUSEHWHEEL))
+    {
+        bool horizontal = msg == WM_MOUSEHWHEEL || (GET_KEYSTATE_WPARAM(wp) & MK_SHIFT);
+        int &remainder = horizontal ? layout->horizontalWheelRemainder : layout->wheelRemainder;
+        remainder += GET_WHEEL_DELTA_WPARAM(wp);
+        int steps = remainder / WHEEL_DELTA;
+        remainder %= WHEEL_DELTA;
+        (horizontal ? layout->x : layout->y) += steps * scale(w, 48) * (msg == WM_MOUSEHWHEEL ? 1 : -1);
+        arrangeWindow(w);
+        return 0;
+    }
+    if (msg == WM_NCDESTROY)
+    {
+        RemovePropW(w, L"WindowLayout");
+        RemoveWindowSubclass(w, layoutProc, 2);
+        delete layout;
+    }
+    return DefSubclassProc(w, msg, wp, lp);
+}
 HWND control(HWND parent, const wchar_t *cls, const wchar_t *title, DWORD style, int id, int x, int y,
              int width, int height)
 {
@@ -34,6 +159,12 @@ HWND control(HWND parent, const wchar_t *cls, const wchar_t *title, DWORD style,
                              scale(parent, width), scale(parent, height), parent, (HMENU)(INT_PTR)id,
                              GetModuleHandleW(nullptr), nullptr);
     SendMessageW(w, WM_SETFONT, (WPARAM)GetPropW(parent, L"Font"), TRUE);
+    if (auto *layout = windowLayoutState(parent); layout && layout->scrolling)
+    {
+        layout->controls.push_back({w, {x, y, x + width, y + height}});
+        SetWindowSubclass(w, scrollChildProc, 2, 0);
+        arrangeWindow(parent);
+    }
     return w;
 }
 void label(HWND w, const wchar_t *text, int x, int y, int width = 200)
@@ -55,13 +186,13 @@ LRESULT CALLBACK hotkeyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DW
     auto *app = (App *)data;
     if (msg == WM_SETFOCUS)
     {
-        app->hotkeyCapture = w;
+        app->setHotkeyCapture(w);
         SendMessageW(w, EM_SETSEL, 0, -1);
     }
     if (msg == WM_KILLFOCUS || msg == WM_NCDESTROY)
     {
         if (app->hotkeyCapture == w)
-            app->hotkeyCapture = nullptr;
+            app->setHotkeyCapture(nullptr);
     }
     if (msg == CaptureHotkeyMessage)
     {
@@ -88,13 +219,13 @@ LRESULT CALLBACK hotkeyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DW
         return 0;
     return DefSubclassProc(w, msg, wp, lp);
 }
-void hotkeyEdit(App &app, HWND w, int id, int x, int y, int width)
+[[maybe_unused]] void hotkeyEdit(App &app, HWND w, int id, int x, int y, int width)
 {
     HWND field = edit(w, id, x, y, width, 25, ES_AUTOHSCROLL | ES_READONLY);
     SendMessageW(field, EM_SETCUEBANNER, FALSE, (LPARAM)L"Click, then press a shortcut");
     SetWindowSubclass(field, hotkeyProc, 1, (DWORD_PTR)&app);
 }
-void checkbox(HWND w, const wchar_t *text, int id, int x, int y, int width = 300)
+[[maybe_unused]] void checkbox(HWND w, const wchar_t *text, int id, int x, int y, int width = 300)
 {
     control(w, L"BUTTON", text, WS_TABSTOP | BS_AUTOCHECKBOX, id, x, y, width, 24);
 }
@@ -111,11 +242,11 @@ void value(HWND w, int id, const std::wstring &text)
 {
     SetDlgItemTextW(w, id, text.c_str());
 }
-bool checked(HWND w, int id)
+[[maybe_unused]] bool checked(HWND w, int id)
 {
     return IsDlgButtonChecked(w, id) == BST_CHECKED;
 }
-void check(HWND w, int id, bool yes)
+[[maybe_unused]] void check(HWND w, int id, bool yes)
 {
     CheckDlgButton(w, id, yes ? BST_CHECKED : BST_UNCHECKED);
 }
@@ -136,13 +267,31 @@ HWND makeWindow(App &app, const wchar_t *cls, const wchar_t *title, WNDPROC proc
     RegisterClassW(&wc);
     UINT dpi = GetDpiForSystem();
     RECT rect{0, 0, MulDiv(width, dpi, 96), MulDiv(height, dpi, 96)};
-    DWORD style = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | extra;
+    DWORD style = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_THICKFRAME | WS_MAXIMIZEBOX | extra;
     AdjustWindowRectExForDpi(&rect, style, FALSE, WS_EX_APPWINDOW, dpi);
+    POINT cursor{};
+    GetCursorPos(&cursor);
+    MONITORINFO monitor{sizeof(monitor)};
+    GetMonitorInfoW(MonitorFromPoint(cursor, MONITOR_DEFAULTTONEAREST), &monitor);
     HWND w =
-        CreateWindowExW(WS_EX_APPWINDOW, cls, title, style, CW_USEDEFAULT, CW_USEDEFAULT,
+        CreateWindowExW(WS_EX_APPWINDOW, cls, title, style, monitor.rcWork.left, monitor.rcWork.top,
                         rect.right - rect.left, rect.bottom - rect.top, nullptr, nullptr, app.instance, &app);
     if (!w)
         throw std::runtime_error(utf8(lastError(L"Cannot create native window")));
+    // The system DPI may still describe the old primary display. The HWND tells
+    // us the actual destination DPI, and must size the frame AND its controls.
+    dpi = GetDpiForWindow(w);
+    rect = {0, 0, MulDiv(width, dpi, 96), MulDiv(height, dpi, 96)};
+    AdjustWindowRectExForDpi(&rect, style, FALSE, WS_EX_APPWINDOW, dpi);
+    int outerWidth = rect.right - rect.left, outerHeight = rect.bottom - rect.top;
+    int left = monitor.rcWork.left + std::max(0L, (monitor.rcWork.right - monitor.rcWork.left - outerWidth) / 2);
+    int top = monitor.rcWork.top + std::max(0L, (monitor.rcWork.bottom - monitor.rcWork.top - outerHeight) / 2);
+    SetPropW(w, L"WindowLayout", new WindowLayout{width, height, 0, 0, !(extra & WS_THICKFRAME)});
+    SetWindowSubclass(w, layoutProc, 2, 0);
+    RECT initial = fitWindowRect({left, top, left + outerWidth, top + outerHeight}, monitor.rcWork);
+    SetWindowPos(w, nullptr, initial.left, initial.top, initial.right - initial.left, initial.bottom - initial.top,
+                 SWP_NOACTIVATE | SWP_NOZORDER);
+    arrangeWindow(w);
     SetWindowTextW(w, title);
     auto smallIcon = (HICON)LoadImageW(app.instance, MAKEINTRESOURCEW(IDI_KSWITCHER), IMAGE_ICON,
                                        GetSystemMetricsForDpi(SM_CXSMICON, dpi),
@@ -154,6 +303,12 @@ HWND makeWindow(App &app, const wchar_t *cls, const wchar_t *title, WNDPROC proc
 }
 void resizeForDpi(HWND w, WPARAM wp, LPARAM lp)
 {
+    // Creation may send WM_DPICHANGED before controls and the original font exist.
+    if (!GetPropW(w, L"Dpi"))
+    {
+        fitToMonitor(w, *(RECT *)lp);
+        return;
+    }
     int previous = (int)(UINT_PTR)GetPropW(w, L"Dpi");
     int next = LOWORD(wp);
     if (!previous)
@@ -166,7 +321,8 @@ void resizeForDpi(HWND w, WPARAM wp, LPARAM lp)
         int previous, next;
         HFONT font;
     } state{w, previous, next, replacement};
-    EnumChildWindows(
+    auto *layout = windowLayoutState(w);
+    if (!layout || !layout->scrolling) EnumChildWindows(
         w,
         [](HWND child, LPARAM data) -> BOOL
         {
@@ -183,14 +339,21 @@ void resizeForDpi(HWND w, WPARAM wp, LPARAM lp)
             return TRUE;
         },
         (LPARAM)&state);
+    else
+    {
+        layout->x = MulDiv(layout->x, next, previous);
+        layout->y = MulDiv(layout->y, next, previous);
+        for (auto &[child, rect] : layout->controls)
+            SendMessageW(child, WM_SETFONT, (WPARAM)replacement, TRUE);
+    }
     SetPropW(w, L"Font", replacement);
     SetPropW(w, L"Dpi", (HANDLE)(UINT_PTR)next);
     if (old)
         DeleteObject(old);
-    auto *r = (RECT *)lp;
-    SetWindowPos(w, nullptr, r->left, r->top, r->right - r->left, r->bottom - r->top, SWP_NOZORDER);
+    fitToMonitor(w, *(RECT *)lp);
+    arrangeWindow(w);
 }
-std::filesystem::path pickFile(HWND owner, bool save)
+[[maybe_unused]] std::filesystem::path pickFile(HWND owner, bool save)
 {
     wchar_t path[32768]{};
     OPENFILENAMEW ofn{sizeof(ofn)};
@@ -210,6 +373,7 @@ void disposeFont(HWND w)
         DeleteObject(h);
 }
 
+#ifndef KS_CONFIG_APP
 struct SearchResult
 {
     uint64_t generation;
@@ -593,6 +757,8 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
     return DefWindowProcW(w, msg, wp, lp);
 }
 
+#endif
+#ifndef KS_RESIDENT_APP
 struct SettingsView
 {
     App *app{};
@@ -645,6 +811,7 @@ void fillSettings(HWND w, SettingsView *v)
     auto &s = v->draft;
     check(w, 201, s.recent);
     check(w, 202, s.switchLayout);
+    check(w, 208, s.writeLog);
     check(w, 203, s.history);
     check(w, 204, s.autostart);
     check(w, 206, s.elevatedAutostart);
@@ -693,6 +860,7 @@ Settings collectSettings(HWND w, SettingsView *v)
     auto s = v->draft;
     s.recent = checked(w, 201);
     s.switchLayout = checked(w, 202);
+    s.writeLog = checked(w, 208);
     s.history = checked(w, 203);
     s.autostart = checked(w, 204);
     s.elevatedAutostart = checked(w, 206);
@@ -908,6 +1076,11 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 layoutSelection(w, v);
                 return 0;
             }
+            if (id == 256)
+            {
+                showLogs(*v->app);
+                return 0;
+            }
             if (id == 230)
             {
                 collectLayout(w, v);
@@ -977,11 +1150,11 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 fillSettings(w, v);
                 return 0;
             }
-            if (id == 254 && v->app->history)
+            if (id == 254)
             {
                 if (MessageBoxW(w, L"Delete all clipboard history, including pinned items?", L"Clear history",
                                 MB_YESNO | MB_ICONWARNING) == IDYES)
-                    v->app->history->clear();
+                    v->app->clearHistory();
                 return 0;
             }
             break;
@@ -1125,6 +1298,8 @@ LRESULT CALLBACK snippetProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
     }
     return DefWindowProcW(w, msg, wp, lp);
 }
+#endif
+#ifndef KS_CONFIG_APP
 LRESULT CALLBACK entryProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 {
     if (msg == WM_SIZE)
@@ -1136,7 +1311,9 @@ LRESULT CALLBACK entryProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
         disposeFont(w);
     return DefWindowProcW(w, msg, wp, lp);
 }
+#endif
 } // namespace
+#ifndef KS_CONFIG_APP
 void refreshHistory(App &app)
 {
     if (app.historyWindow)
@@ -1195,7 +1372,254 @@ void showHistory(App &app)
     SetFocus(GetDlgItem(app.historyWindow, 101));
     refreshHistory(app);
 }
-void showSettings(App &app)
+namespace
+{
+constexpr int LogChoice = 601, LogRows = 602, LogRefresh = 603, LogStatus = 604, LogCopy = 605,
+              LogClear = 606;
+LRESULT CALLBACK logListProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
+{
+    // Header notifications go to the ListView, not its top-level parent.
+    if (msg == WM_NOTIFY && ((NMHDR *)lp)->hwndFrom == ListView_GetHeader(w) &&
+        ((NMHDR *)lp)->code == NM_CUSTOMDRAW)
+    {
+        auto *draw = (NMCUSTOMDRAW *)lp;
+        if (draw->dwDrawStage == CDDS_PREPAINT)
+        {
+            FillRect(draw->hdc, &draw->rc, GetSysColorBrush(COLOR_BTNFACE));
+            return CDRF_NOTIFYITEMDRAW;
+        }
+        if (draw->dwDrawStage == CDDS_ITEMPREPAINT)
+        {
+            int saved = SaveDC(draw->hdc);
+            FillRect(draw->hdc, &draw->rc, GetSysColorBrush(COLOR_BTNFACE));
+            RECT edge = draw->rc;
+            edge.top = edge.bottom - 1;
+            FillRect(draw->hdc, &edge, GetSysColorBrush(COLOR_3DSHADOW));
+            edge = draw->rc;
+            edge.left = edge.right - 1;
+            FillRect(draw->hdc, &edge, GetSysColorBrush(COLOR_3DSHADOW));
+            wchar_t title[128]{};
+            HDITEMW item{};
+            item.mask = HDI_TEXT;
+            item.pszText = title;
+            item.cchTextMax = 128;
+            Header_GetItem(draw->hdr.hwndFrom, (int)draw->dwItemSpec, &item);
+            auto headerFont = (HFONT)SendMessageW(draw->hdr.hwndFrom, WM_GETFONT, 0, 0);
+            if (headerFont)
+                SelectObject(draw->hdc, headerFont);
+            SetBkMode(draw->hdc, TRANSPARENT);
+            SetTextColor(draw->hdc, GetSysColor(COLOR_BTNTEXT));
+            RECT text = draw->rc;
+            InflateRect(&text, -scale(w, 6), 0);
+            DrawTextW(draw->hdc, title, -1, &text, DT_SINGLELINE | DT_VCENTER | DT_END_ELLIPSIS | DT_NOPREFIX);
+            RestoreDC(draw->hdc, saved);
+            return CDRF_SKIPDEFAULT;
+        }
+    }
+    if (msg == WM_NCDESTROY)
+        RemoveWindowSubclass(w, logListProc, 1);
+    return DefSubclassProc(w, msg, wp, lp);
+}
+void copyLogRows(HWND w, App &app)
+{
+    HWND list = GetDlgItem(w, LogRows);
+    std::wstring copied;
+    for (int row = ListView_GetNextItem(list, -1, LVNI_SELECTED); row >= 0;
+         row = ListView_GetNextItem(list, row, LVNI_SELECTED))
+    {
+        for (int column = 0; column < 4; ++column)
+        {
+            std::vector<wchar_t> text(32768);
+            ListView_GetItemText(list, row, column, text.data(), (int)text.size());
+            if (column)
+                copied += L'\t';
+            copied += text.data();
+        }
+        copied += L"\r\n";
+    }
+    if (!copied.empty())
+        app.ownSequence = writeClipboard(app.window, textClip(copied));
+}
+void refreshLogView(HWND w, App &app)
+{
+    const bool previous = SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1;
+    std::wstring contents;
+    try
+    {
+        contents = readDiagnosticLog(previous);
+    }
+    catch (const std::exception &e)
+    {
+        contents = L"Could not read the log: " + wide(e.what());
+    }
+    HWND list = GetDlgItem(w, LogRows);
+    SendMessageW(list, WM_SETREDRAW, FALSE, 0);
+    ListView_DeleteAllItems(list);
+    std::wistringstream lines(contents);
+    std::wstring line, timestamp;
+    int row = 0;
+    while (std::getline(lines, line))
+    {
+        if (!line.empty() && line.back() == L'\r')
+            line.pop_back();
+        if (line.empty())
+            continue;
+        auto firstSpace = line.find(L' ');
+        auto secondSpace = firstSpace == line.npos ? line.npos : line.find(L' ', firstSpace + 1);
+        if (iswdigit(line.front()) && line.find(L'-') < firstSpace && secondSpace != line.npos)
+        {
+            timestamp = line.substr(0, secondSpace);
+            line.erase(0, secondSpace + 1);
+        }
+        auto id = line.find(L" id=");
+        std::wstring attempt;
+        if (id != line.npos)
+        {
+            auto end = line.find(L' ', id + 4);
+            attempt = line.substr(id + 4, end == line.npos ? end : end - id - 4);
+        }
+        std::wstring event = line;
+        if (event.starts_with(L"  ageMs="))
+        {
+            auto end = event.find(L' ', 8);
+            if (end != event.npos)
+                event.erase(0, end + 1);
+        }
+        auto equals = event.find(L'=');
+        if (equals != event.npos)
+        {
+            auto key = event.rfind(L' ', equals);
+            if (key != event.npos)
+                event.resize(key);
+        }
+        LVITEMW item{};
+        item.mask = LVIF_TEXT;
+        item.iItem = row;
+        item.pszText = timestamp.data();
+        ListView_InsertItem(list, &item);
+        ListView_SetItemText(list, row, 1, attempt.data());
+        ListView_SetItemText(list, row, 2, event.data());
+        ListView_SetItemText(list, row, 3, line.data());
+        ++row;
+    }
+    SendMessageW(list, WM_SETREDRAW, TRUE, 0);
+    InvalidateRect(list, nullptr, TRUE);
+    if (row)
+        ListView_EnsureVisible(list, row - 1, FALSE);
+    value(w, LogStatus, app.settings.writeLog ? L"Logging enabled: failed operations only."
+                                    : L"Logging disabled. Showing previously saved entries.");
+}
+LRESULT CALLBACK logProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
+{
+    auto *app = reinterpret_cast<App *>(GetWindowLongPtrW(w, GWLP_USERDATA));
+    if (msg == WM_NCCREATE)
+    {
+        SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)((CREATESTRUCTW *)lp)->lpCreateParams);
+        return TRUE;
+    }
+    if (!app)
+        return DefWindowProcW(w, msg, wp, lp);
+    switch (msg)
+    {
+    case WM_COMMAND:
+        if ((LOWORD(wp) == LogRefresh && HIWORD(wp) == BN_CLICKED) ||
+            (LOWORD(wp) == LogChoice && HIWORD(wp) == CBN_SELCHANGE))
+        {
+            refreshLogView(w, *app);
+            return 0;
+        }
+        if (LOWORD(wp) == LogCopy && HIWORD(wp) == BN_CLICKED)
+        {
+            try { copyLogRows(w, *app); }
+            catch (const std::exception &e) { error(w, e); }
+            return 0;
+        }
+        if (LOWORD(wp) == LogClear && HIWORD(wp) == BN_CLICKED)
+        {
+            try
+            {
+                clearDiagnosticLog(SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1);
+                refreshLogView(w, *app);
+            }
+            catch (const std::exception &e) { error(w, e); }
+            return 0;
+        }
+        if (LOWORD(wp) != IDCANCEL || HIWORD(wp) != BN_CLICKED)
+            break;
+        [[fallthrough]];
+    case WM_CLOSE:
+        DestroyWindow(w);
+        return 0;
+    case WM_NOTIFY:
+        if (((NMHDR *)lp)->idFrom == LogRows && ((NMHDR *)lp)->code == LVN_KEYDOWN)
+        {
+            auto key = ((NMLVKEYDOWN *)lp)->wVKey;
+            if (GetKeyState(VK_CONTROL) & 0x8000)
+            {
+                if (key == 'A')
+                    ListView_SetItemState(GetDlgItem(w, LogRows), -1, LVIS_SELECTED, LVIS_SELECTED);
+                if (key == 'C')
+                {
+                    try { copyLogRows(w, *app); }
+                    catch (const std::exception &e) { error(w, e); }
+                }
+            }
+        }
+        return 0;
+    case WM_DPICHANGED:
+        resizeForDpi(w, wp, lp);
+        return 0;
+    case WM_NCDESTROY:
+        app->logWindow = nullptr;
+        disposeFont(w);
+        break;
+    }
+    return DefWindowProcW(w, msg, wp, lp);
+}
+}
+void showLogs(App &app)
+{
+    if (app.logWindow)
+    {
+        showRequestedWindow(app.logWindow);
+        activateWindow(app.logWindow);
+        return;
+    }
+    auto w = makeWindow(app, L"KSwitcher.Logs", L"KSwitcher log", logProc, 900, 590);
+    app.logWindow = w;
+    auto choice = control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST, LogChoice, 16, 16, 300, 140);
+    SendMessageW(choice, CB_ADDSTRING, 0, (LPARAM)L"Current log — kswitcher.log");
+    SendMessageW(choice, CB_ADDSTRING, 0, (LPARAM)L"Previous log — kswitcher.log.1");
+    SendMessageW(choice, CB_SETCURSEL, 0, 0);
+    button(w, L"Refresh", LogRefresh, 330, 14, 110);
+    button(w, L"Copy selected", LogCopy, 454, 14, 140);
+    button(w, L"Clear log", LogClear, 608, 14, 110);
+    control(w, L"STATIC", L"", 0, LogStatus, 16, 52, 860, 22);
+    INITCOMMONCONTROLSEX common{sizeof(common), ICC_LISTVIEW_CLASSES};
+    InitCommonControlsEx(&common);
+    auto list = control(w, WC_LISTVIEWW, L"", WS_TABSTOP | WS_BORDER | LVS_REPORT | LVS_SHOWSELALWAYS,
+                        LogRows, 16, 82, 868, 454);
+    ListView_SetExtendedListViewStyle(list, LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES | LVS_EX_DOUBLEBUFFER);
+    SetWindowSubclass(list, logListProc, 1, 0);
+    const wchar_t *titles[] = {L"Time", L"Attempt", L"Event", L"Details"};
+    const int widths[] = {155, 65, 195, 900};
+    for (int i = 0; i < 4; ++i)
+    {
+        LVCOLUMNW column{};
+        column.mask = LVCF_TEXT | LVCF_WIDTH;
+        column.pszText = const_cast<wchar_t *>(titles[i]);
+        column.cx = scale(w, widths[i]);
+        ListView_InsertColumn(list, i, &column);
+    }
+    label(w, L"Select rows to copy. Ctrl+A selects all; Ctrl+C copies selected rows.", 16, 551, 720);
+    button(w, L"Close", IDCANCEL, 774, 548, 110);
+    refreshLogView(w, app);
+    showRequestedWindow(w);
+    activateWindow(w);
+}
+#endif
+#ifndef KS_RESIDENT_APP
+void showSettings(App &app, bool visible)
 {
     if (app.settingsWindow)
     {
@@ -1209,12 +1633,13 @@ void showSettings(App &app)
     HWND w = makeWindow(app, L"KSwitcher.Settings", L"KSwitcher settings", settingsProc, 780, 660);
     app.settingsWindow = w;
     label(w, L"Text conversion", 18, 16);
-    checkbox(w, L"Convert recently typed text when nothing is selected", 201, 18, 43, 440);
-    checkbox(w, L"Switch Windows input layout after conversion", 202, 18, 70, 440);
+    checkbox(w, L"Convert recently typed text when nothing is selected", 201, 18, 43, 390);
+    checkbox(w, L"Switch Windows input layout after conversion", 202, 18, 70, 390);
     checkbox(w, L"Record clipboard history", 203, 18, 106);
     checkbox(w, L"Start with Windows", 204, 18, 133);
     checkbox(w, L"Start with Windows as administrator", 206, 18, 160, 395);
-    checkbox(w, L"Keep screen awake", 205, 18, 184);
+    checkbox(w, L"Keep screen awake", 205, 18, 184, 210);
+    checkbox(w, L"Write log", 208, 240, 184, 160);
     label(w, L"Click a shortcut and press the desired keys", 420, 16, 350);
     const wchar_t *names[] = {L"Next layout", L"Change case", L"Transliterate", L"Undo",
                               L"Clipboard history"};
@@ -1245,14 +1670,18 @@ void showSettings(App &app)
     label(w, L"Exclude applications (process names, comma-separated)", 18, 516, 700);
     edit(w, 243, 18, 544, 742);
     button(w, L"Auto-correction options…", 255, 18, 575, 240);
+    button(w, L"View log…", 256, 278, 575, 220);
     button(w, L"Import settings…", 250, 18, 606, 145);
     button(w, L"Export settings…", 251, 173, 606, 145);
     button(w, L"Snippets…", 252, 328, 606, 110);
     button(w, L"Save", IDOK, 548, 606, 100);
     button(w, L"Cancel", IDCANCEL, 660, 606, 100);
     fillSettings(w, (SettingsView *)GetWindowLongPtrW(w, GWLP_USERDATA));
-    showRequestedWindow(w);
-    activateWindow(w);
+    if (visible)
+    {
+        showRequestedWindow(w);
+        activateWindow(w);
+    }
 }
 void showSnippets(App &app)
 {
@@ -1280,6 +1709,11 @@ void showSnippets(App &app)
     showRequestedWindow(w);
     SetForegroundWindow(w);
 }
+#else
+void showSettings(App &app, bool) { launchConfiguration(app); }
+void showSnippets(App &app) { launchConfiguration(app, true); }
+#endif
+#ifndef KS_CONFIG_APP
 void showShortcuts(App &app)
 {
     auto &s = app.settings;
@@ -1317,4 +1751,5 @@ void showEntry(App &app, const std::wstring &id)
         error(app.historyWindow, e);
     }
 }
+#endif
 } // namespace ks

src/ui_geometry.h

@@ -0,0 +1,14 @@
+#pragma once
+#include "core.h"
+#include <algorithm>
+namespace ks
+{
+inline RECT fitWindowRect(RECT desired, RECT work)
+{
+    LONG width = std::clamp<LONG>(desired.right - desired.left, 1, std::max<LONG>(1, work.right - work.left));
+    LONG height = std::clamp<LONG>(desired.bottom - desired.top, 1, std::max<LONG>(1, work.bottom - work.top));
+    LONG x = std::clamp(desired.left, work.left, work.right - width);
+    LONG y = std::clamp(desired.top, work.top, work.bottom - height);
+    return {x, y, x + width, y + height};
+}
+}

src/update.cpp

@@ -0,0 +1,103 @@
+#include "update.h"
+#include "json.hpp"
+
+namespace ks
+{
+namespace
+{
+struct Handle
+{
+    HANDLE value{};
+    ~Handle() { if (value) CloseHandle(value); }
+};
+std::wstring quoteArgument(const std::wstring &value)
+{
+    // Windows argv escaping, including a path ending with a backslash.
+    std::wstring out = L"\"";
+    size_t slashes = 0;
+    for (auto ch : value)
+    {
+        if (ch == L'\\') { ++slashes; continue; }
+        out.append(ch == L'"' ? slashes * 2 + 1 : slashes, L'\\');
+        slashes = 0;
+        out += ch;
+    }
+    out.append(slashes * 2, L'\\');
+    return out + L'"';
+}
+}
+UpdateResult runUpdate(bool install, const std::wstring &expectedVersion)
+{
+    UpdateResult result;
+    GUID guid{};
+    if (FAILED(CoCreateGuid(&guid))) throw std::runtime_error("Cannot create update identifier");
+    wchar_t id[40]{};
+    StringFromGUID2(guid, id, 40);
+    auto work = std::filesystem::temp_directory_path() / (L"KSwitcher-update-" + std::wstring(id));
+    std::filesystem::create_directory(work);
+    bool detached = false;
+    Handle child;
+    try
+    {
+        HRSRC resource = FindResourceW(nullptr, MAKEINTRESOURCEW(201), RT_RCDATA);
+        HGLOBAL loaded = resource ? LoadResource(nullptr, resource) : nullptr;
+        auto bytes = loaded ? static_cast<const unsigned char *>(LockResource(loaded)) : nullptr;
+        if (!bytes) throw std::runtime_error("The updater resource is missing");
+        atomicWrite(work / L"update.ps1", Bytes(bytes, bytes + SizeofResource(nullptr, resource)));
+        std::wstring readyName = L"Local\\KSwitcher.Update.Ready." + std::wstring(id);
+        Handle ready{CreateEventW(nullptr, TRUE, FALSE, readyName.c_str())};
+        if (!ready.value) throw std::runtime_error("Cannot create updater handshake");
+        wchar_t system[MAX_PATH]{};
+        if (!GetSystemDirectoryW(system, MAX_PATH)) throw std::runtime_error("Cannot locate Windows PowerShell");
+        auto powershell = std::filesystem::path(system) / L"WindowsPowerShell/v1.0/powershell.exe";
+        std::wstring command = quoteArgument(powershell.wstring()) + L" -NoLogo -NoProfile -NonInteractive -ExecutionPolicy Bypass -File " +
+            quoteArgument((work / L"update.ps1").wstring()) + L" -Mode " + (install ? L"Install" : L"Check") +
+            L" -CurrentVersion " + quoteArgument(AppVersion) + L" -WorkDirectory " + quoteArgument(work.wstring()) +
+            L" -InstallDirectory " + quoteArgument(std::filesystem::path(executable()).parent_path().wstring()) +
+            L" -ParentProcessId " + std::to_wstring(GetCurrentProcessId()) + L" -ReadyEvent " + quoteArgument(readyName);
+        if (install) command += L" -ExpectedVersion " + quoteArgument(expectedVersion);
+        STARTUPINFOW startup{sizeof(startup)};
+        PROCESS_INFORMATION process{};
+        if (!CreateProcessW(powershell.c_str(), command.data(), nullptr, nullptr, FALSE, CREATE_NO_WINDOW,
+                            nullptr, work.c_str(), &startup, &process))
+            throw std::runtime_error("Cannot start Windows PowerShell updater");
+        child.value = process.hProcess;
+        Handle thread{process.hThread};
+        HANDLE waits[]{ready.value, child.value};
+        DWORD waited = WaitForMultipleObjects(2, waits, FALSE, 240000);
+        if (waited != WAIT_OBJECT_0 && waited != WAIT_OBJECT_0 + 1)
+        {
+            // The helper cannot replace files while this process is alive.
+            TerminateProcess(child.value, 1);
+            WaitForSingleObject(child.value, 5000);
+            throw std::runtime_error("Update preparation timed out; the installed application was not changed");
+        }
+        auto data = readFile(work / L"result.json", 64 * 1024);
+        auto json = nlohmann::json::parse(data.begin(), data.end());
+        result.state = wide(json.at("state").get<std::string>());
+        result.version = wide(json.value("version", std::string{}));
+        result.error = wide(json.value("error", std::string{}));
+        detached = install && waited == WAIT_OBJECT_0 && result.state == L"prepared";
+        if (result.state == L"prepared" && !detached)
+            throw std::runtime_error("Update helper exited before installation");
+        if (!detached) std::filesystem::remove_all(work);
+        return result;
+    }
+    catch (...)
+    {
+        if (!detached && child.value && WaitForSingleObject(child.value, 0) == WAIT_TIMEOUT)
+        {
+            TerminateProcess(child.value, 1);
+            WaitForSingleObject(child.value, 5000);
+        }
+        if (!detached) { std::error_code ignored; std::filesystem::remove_all(work, ignored); }
+        throw;
+    }
+}
+void confirmUpdatedStartup(const std::wstring &eventName)
+{
+    if (!eventName.starts_with(L"Local\\KSwitcher.Update.Started.")) return;
+    Handle event{OpenEventW(EVENT_MODIFY_STATE, FALSE, eventName.c_str())};
+    if (event.value) SetEvent(event.value);
+}
+}

src/update.h

@@ -0,0 +1,14 @@
+#pragma once
+#include "platform.h"
+namespace ks
+{
+inline constexpr wchar_t AppVersion[] = L"0.3.0";
+inline constexpr UINT UpdateMessage = WM_APP + 7;
+struct UpdateResult
+{
+    std::wstring state, version, error;
+    bool interactive{}, install{};
+};
+UpdateResult runUpdate(bool install, const std::wstring &expectedVersion);
+void confirmUpdatedStartup(const std::wstring &eventName);
+}

tests/configuration.ps1

@@ -0,0 +1,143 @@
+param([string]$BuildDirectory = (Join-Path $PSScriptRoot '../build/staged'))
+$ErrorActionPreference = 'Stop'
+if (Get-Process KSwitcher,'KSwitcher.Config' -ErrorAction SilentlyContinue) {
+    throw 'Close KSwitcher and its configurator before this isolated process test.'
+}
+Add-Type @'
+using System;
+using System.Runtime.InteropServices;
+public static class ConfigurationTestUi {
+ [StructLayout(LayoutKind.Explicit, Size=40)] public struct Input {
+  [FieldOffset(0)] public uint type;
+  [FieldOffset(8)] public ushort key;
+  [FieldOffset(12)] public uint flags;
+ }
+ [DllImport("user32.dll")] public static extern uint SendInput(uint count,Input[] input,int size);
+ public static uint PressF24() { return SendInput(2,new Input[]{new Input{type=1,key=0x87},new Input{type=1,key=0x87,flags=2}},40); }
+ [DllImport("user32.dll")] public static extern IntPtr GetForegroundWindow();
+ [DllImport("user32.dll", EntryPoint="SendMessageW", CharSet=CharSet.Unicode)] public static extern IntPtr GetText(IntPtr w,uint msg,IntPtr count,System.Text.StringBuilder text);
+ [DllImport("user32.dll", CharSet=CharSet.Unicode)] public static extern IntPtr FindWindow(string cls,string title);
+ [DllImport("user32.dll")] public static extern IntPtr GetDlgItem(IntPtr w,int id);
+ [DllImport("user32.dll")] public static extern bool PostMessage(IntPtr w,uint msg,IntPtr wp,IntPtr lp);
+ [DllImport("user32.dll")] public static extern IntPtr SendMessage(IntPtr w,uint msg,IntPtr wp,IntPtr lp);
+ [DllImport("user32.dll", EntryPoint="SendMessageW", CharSet=CharSet.Unicode)] public static extern IntPtr SetText(IntPtr w,uint msg,IntPtr wp,string text);
+ [DllImport("user32.dll")] public static extern uint GetWindowThreadProcessId(IntPtr w,out uint pid);
+ [DllImport("kernel32.dll")] public static extern uint GetCurrentThreadId();
+ [DllImport("user32.dll")] public static extern bool AttachThreadInput(uint a,uint b,bool attach);
+ [DllImport("user32.dll")] public static extern IntPtr SetFocus(IntPtr w);
+ public static bool FocusControl(IntPtr w) {
+  uint pid; uint target=GetWindowThreadProcessId(w,out pid), current=GetCurrentThreadId();
+  if(!AttachThreadInput(current,target,true)) return false;
+  try { SetFocus(w); return true; } finally { AttachThreadInput(current,target,false); }
+ }
+}
+'@
+$root=Join-Path ([IO.Path]::GetTempPath()) ('KSwitcher-config-tests-'+[guid]::NewGuid().ToString('N'))
+$processes=[Collections.Generic.List[Diagnostics.Process]]::new()
+$checks=0
+function Assert($ok,$label) { if (!$ok) { throw $label }; $script:checks++ }
+function Window($class) {
+    for($i=0;$i -lt 100;$i++) {
+        $title=switch($class){'KSwitcher.Main'{'KSwitcher'};'KSwitcher.Settings'{'KSwitcher settings'};'KSwitcher.Snippets'{'Text snippets'}}
+        $window=[ConfigurationTestUi]::FindWindow($class,$title)
+        if($window -ne [IntPtr]::Zero){return $window}
+        Start-Sleep -Milliseconds 50
+    }
+    foreach($process in $processes){$process.Refresh(); Write-Host ("Diagnostic process {0}: exited={1} title={2}" -f $process.Id,$process.HasExited,$process.MainWindowTitle)}
+    throw "Window did not appear: $class"
+}
+function Launch($file,$argument) {
+    $options=@{FilePath=(Join-Path $root $file);PassThru=$true;WindowStyle='Hidden'}
+    if($argument){$options.ArgumentList=$argument}
+    $process=Start-Process @options
+    $processes.Add($process)
+    return $process
+}
+function Click($window,$id) {
+    $null=[ConfigurationTestUi]::PostMessage($window,0x111,[IntPtr]$id,[IntPtr]::Zero)
+}
+try {
+    New-Item -ItemType Directory -Path (Join-Path $root 'data') -Force | Out-Null
+    foreach($file in @('KSwitcher.exe','KSwitcher.Config.exe')) {
+        Copy-Item -LiteralPath (Join-Path $BuildDirectory $file) -Destination $root
+    }
+    # No clipboard history capture, auto-correction, autostart or user data in the fixture.
+    $settingsPath=Join-Path $root 'data/settings.json'
+    @{format='kswitcher-settings';schemaVersion=1;historyEnabled=$false;autoCorrectLayout=$false;writeLog=$false} |
+        ConvertTo-Json | Set-Content -LiteralPath $settingsPath -Encoding utf8
+    $resident=Launch 'KSwitcher.exe' ''
+    $main=Window 'KSwitcher.Main'
+    $config=Launch 'KSwitcher.Config.exe' ''
+    $settings=Window 'KSwitcher.Settings'
+    [uint32]$ownerId=0
+    $null=[ConfigurationTestUi]::GetWindowThreadProcessId($settings,[ref]$ownerId)
+    Assert ($ownerId -eq $config.Id -and $ownerId -ne $resident.Id) 'settings live in the separate process'
+    $second=Launch 'KSwitcher.Config.exe' ''
+    Assert ($second.WaitForExit(6000) -and $second.ExitCode -eq 0) 'second launch forwards to existing instance'
+    Assert ((Window 'KSwitcher.Settings') -eq $settings) 'existing settings window reused'
+    # Only inject into the isolated fixture window, never another foreground app.
+    Assert ([ConfigurationTestUi]::GetForegroundWindow() -eq $settings) 'fixture owns foreground before shortcut capture test'
+    $field=[ConfigurationTestUi]::GetDlgItem($settings,210)
+    Assert ([ConfigurationTestUi]::FocusControl($field)) 'shortcut field receives actual focus'
+    Assert ([ConfigurationTestUi]::PressF24() -eq 2) 'test F24 events accepted'
+    $text=[Text.StringBuilder]::new(128)
+    for($i=0;$i -lt 100;$i++) {
+        $null=$text.Clear()
+        $null=[ConfigurationTestUi]::GetText($field,0x0d,[IntPtr]128,$text)
+        if($text.ToString() -eq 'F24'){break}
+        Start-Sleep -Milliseconds 20
+    }
+    Assert ($text.ToString() -eq 'F24') 'resident hook forwards shortcut capture to configurator'
+    $null=[ConfigurationTestUi]::SetText([ConfigurationTestUi]::GetDlgItem($settings,240),0x0c,[IntPtr]::Zero,'321')
+    Click $settings 1
+    Assert ($config.WaitForExit(6000) -and $config.ExitCode -eq 0) 'save exits configurator'
+    Assert ((Get-Content -LiteralPath $settingsPath -Raw | ConvertFrom-Json).maxItems -eq 321) 'save committed through resident process'
+    Assert ((Get-Content -LiteralPath $settingsPath -Raw | ConvertFrom-Json).toggleHotkey -eq 'F24') 'captured shortcut persisted by resident'
+    $resident.Refresh(); Assert (!$resident.HasExited) 'resident survives settings save'
+    $config=Launch 'KSwitcher.Config.exe' ''
+    $settings=Window 'KSwitcher.Settings'
+    $null=[ConfigurationTestUi]::SetText([ConfigurationTestUi]::GetDlgItem($settings,240),0x0c,[IntPtr]::Zero,'456')
+    Click $settings 2
+    Assert ($config.WaitForExit(6000)) 'cancel exits configurator'
+    Assert ((Get-Content -LiteralPath $settingsPath -Raw | ConvertFrom-Json).maxItems -eq 321) 'cancel preserves saved settings'
+    $config=Launch 'KSwitcher.Config.exe' '--snippets'
+    $snippets=Window 'KSwitcher.Snippets'
+    $second=Launch 'KSwitcher.Config.exe' ''
+    Assert ($second.WaitForExit(6000) -and $second.ExitCode -eq 0) 'settings and snippets share a single process'
+    $settings=Window 'KSwitcher.Settings'
+    Click $settings 2
+    Start-Sleep -Milliseconds 100
+    $config.Refresh(); Assert (!$config.HasExited) 'closing settings keeps open snippets alive'
+    Click $snippets 2
+    Assert ($config.WaitForExit(6000)) 'closing last window exits configurator'
+    $config=Launch 'KSwitcher.Config.exe' ''
+    $null=Window 'KSwitcher.Settings'
+    $null=[ConfigurationTestUi]::PostMessage($main,0x10,[IntPtr]::Zero,[IntPtr]::Zero)
+    Assert ($resident.WaitForExit(10000)) 'resident shuts down normally'
+    Assert ($config.WaitForExit(6000)) 'resident exit closes configurator'
+    $config=Launch 'KSwitcher.Config.exe' ''
+    $main=Window 'KSwitcher.Main'
+    [uint32]$bootstrappedId=0
+    $null=[ConfigurationTestUi]::GetWindowThreadProcessId($main,[ref]$bootstrappedId)
+    $bootstrapped=Get-Process -Id $bootstrappedId
+    $processes.Add($bootstrapped)
+    $settings=Window 'KSwitcher.Settings'
+    Assert ($bootstrappedId -ne $resident.Id) 'standalone configurator starts its resident sibling'
+    Click $settings 2
+    Assert ($config.WaitForExit(6000)) 'standalone configurator exits after cancel'
+    $null=[ConfigurationTestUi]::PostMessage($main,0x10,[IntPtr]::Zero,[IntPtr]::Zero)
+    Assert ($bootstrapped.WaitForExit(10000)) 'bootstrapped resident shuts down normally'
+    "Passed $checks configurator process checks"
+} finally {
+    foreach($process in $processes) {
+        $process.Refresh()
+        if(!$process.HasExited) { Stop-Process -Id $process.Id -Force }
+        $process.Dispose()
+    }
+    # The generated fixture is the only recursive deletion target.
+    $resolved=[IO.Path]::GetFullPath($root)
+    $temp=[IO.Path]::GetFullPath([IO.Path]::GetTempPath())
+    if(!$resolved.StartsWith($temp,[StringComparison]::OrdinalIgnoreCase) -or
+       [IO.Path]::GetFileName($resolved) -notlike 'KSwitcher-config-tests-*') { throw 'Unexpected fixture path' }
+    Remove-Item -LiteralPath $resolved -Recurse -Force
+}

tests/input.cpp

@@ -0,0 +1,122 @@
+#include "app.h"
+#include "ui_geometry.h"
+#include <commctrl.h>
+#include <iostream>
+namespace ks {
+struct InputRegressionAccess {
+    static void setup(App &a) { a.hookBindings = {{Toggle,{MOD_CONTROL,VK_F12}}, {Case,{MOD_CONTROL|MOD_SHIFT,'U'}}}; }
+    static void click() { MSLLHOOKSTRUCT m{}; m.flags=LLMHF_INJECTED; App::mouseProc(HC_ACTION,WM_LBUTTONDOWN,(LPARAM)&m); }
+};
+}
+int main(int argc, char **argv) {
+    if (argc == 2 && std::string(argv[1]) == "--update-check") {
+        try {
+            auto result = ks::runUpdate(false, {});
+            std::cout << "Live update check: " << ks::utf8(result.state) << " " << ks::utf8(result.version)
+                      << " " << ks::utf8(result.error) << '\n';
+            return result.state == L"current" || result.state == L"available" ? 0 : 1;
+        } catch (const std::exception &e) { std::cerr << e.what() << '\n'; return 1; }
+    }
+    auto temp=std::filesystem::temp_directory_path()/(L"KSwitcher-input-tests-"+std::to_wstring(GetCurrentProcessId()));
+    int checks=0;
+    auto require=[&](bool ok,const char* text) { if(!ok) throw std::runtime_error(text); ++checks; };
+    try {
+        INITCOMMONCONTROLSEX controls{sizeof(controls),ICC_STANDARD_CLASSES|ICC_LISTVIEW_CLASSES};
+        InitCommonControlsEx(&controls);
+        {
+            ks::App app(GetModuleHandleW(nullptr),true,temp);
+            ks::InputRegressionAccess::setup(app);
+            // Message-only window: no hooks, synthetic input, clipboard changes or visible editor.
+            app.window=CreateWindowExW(0,L"STATIC",L"Input tests",0,0,0,0,0,HWND_MESSAGE,nullptr,nullptr,nullptr);
+            require(app.window!=nullptr,"message-only test window");
+            auto event=[](DWORD vk,DWORD scan=0,bool own=false) {
+                KBDLLHOOKSTRUCT k{}; k.vkCode=vk; k.scanCode=scan;
+                k.flags=LLKHF_INJECTED|LLKHF_LOWER_IL_INJECTED;
+                k.dwExtraInfo=own?ks::inputMarker():123; return k;
+            };
+            auto commands=[&] { MSG m{}; int n=0; while(PeekMessageW(&m,app.window,WM_HOTKEY,WM_HOTKEY,PM_REMOVE)) ++n; return n; };
+            auto f12=event(VK_F12);
+            require(!app.handleKeyboard(event(VK_LCONTROL),true,0),"remote modifier passes through");
+            require(app.handleKeyboard(f12,true,MOD_CONTROL),"remote Ctrl+F12 handled");
+            require(app.handleKeyboard(f12,true,MOD_CONTROL),"remote repeat suppressed");
+            require(commands()==1,"one command per press");
+            require(!app.handleKeyboard(event(VK_F12,0,true),false,0),"own key-up bypasses latch");
+            require(app.handleKeyboard(f12,true,MOD_CONTROL),"own key-up leaves remote latch intact");
+            require(commands()==0,"no repeat after own key-up");
+            require(app.handleKeyboard(f12,false,0),"remote release consumed after modifier release");
+            require(app.handleKeyboard(f12,true,MOD_CONTROL),"second remote press handled");
+            require(commands()==1,"second remote press dispatches");
+            app.handleKeyboard(f12,false,0);
+            require(app.handleKeyboard(event('U'),true,MOD_CONTROL|MOD_SHIFT),"combined modifiers");
+            app.handleKeyboard(event('U'),false,0);
+            require(!app.handleKeyboard(f12,true,MOD_CONTROL|MOD_SHIFT),"exact modifiers only");
+            app.resetInput();
+            app.handleKeyboard(event('A',0x1e),true,0);
+            require(app.run.keys==L"a"||app.run.keys==L"A","external scan recorded with current CapsLock");
+            auto keys=app.run.keys; auto version=app.inputVersion.load();
+            for(WORD key:{WORD('V'),WORD(VK_SHIFT),WORD(VK_LEFT),WORD(VK_F15),WORD(0xE8)})
+                for(bool up:{false,true}) {
+                    auto i=ks::keyboardInput(key,up?KEYEVENTF_KEYUP:0);
+                    require(i.ki.dwExtraInfo==ks::inputMarker(),"all generated events tagged");
+                    require(!app.handleKeyboard(event(key,0,true),!up,MOD_CONTROL),"own events bypass handling");
+                }
+            require(app.run.keys==keys&&app.inputVersion==version,"own input preserves transaction and run");
+            app.handleKeyboard(event(VK_BACK),true,0);
+            require(app.run.keys.empty(),"remote backspace recorded");
+            app.handleKeyboard(event('B'),true,MOD_SHIFT);
+            require(!app.run.keys.empty(),"VK-only remote input resolves scan code");
+            require(app.inputVersion>version,"remote input invalidates pending transaction");
+            app.handleKeyboard(event(VK_PACKET,0x1e),true,0);
+            require(app.run.keys.empty(),"Unicode packet is not a physical scan code");
+            app.handleKeyboard(event('A',0x1e),true,0);
+            ks::InputRegressionAccess::click();
+            require(app.run.keys.empty(),"remote mouse resets recorded input");
+            auto physical=f12; physical.flags=0; physical.dwExtraInfo=ks::inputMarker();
+            require(app.handleKeyboard(physical,true,MOD_CONTROL),"physical hotkey still works");
+            app.handleKeyboard(physical,false,0);
+            auto fitted=ks::fitWindowRect({-2500,-800,-500,1200},{0,0,1200,800});
+            require(fitted.left==0&&fitted.top==0&&fitted.right==1200&&fitted.bottom==800,"oversized disconnected-monitor window fits work area");
+            fitted=ks::fitWindowRect({2000,2000,2600,2400},{-1920,0,0,1080});
+            require(fitted.left==-600&&fitted.top==680&&fitted.right==0,"negative-coordinate monitor supported");
+            ks::showSettings(app,false);
+            auto settings=app.settingsWindow;
+            require(settings&&!IsWindowVisible(settings),"settings layout tested without changing user focus");
+            RECT frame{},client{},cancel{};
+            GetWindowRect(settings,&frame);
+            MONITORINFO monitor{sizeof(monitor)};
+            GetMonitorInfoW(MonitorFromWindow(settings,MONITOR_DEFAULTTONEAREST),&monitor);
+            require(frame.left>=monitor.rcWork.left&&frame.top>=monitor.rcWork.top&&frame.right<=monitor.rcWork.right&&frame.bottom<=monitor.rcWork.bottom,"initial settings frame fits active work area");
+            UINT dpi=GetDpiForWindow(settings);
+            std::cout << "Hidden Settings layout checked at " << dpi << " DPI\n";
+            GetWindowRect(GetDlgItem(settings,IDCANCEL),&cancel);
+            require(cancel.right-cancel.left==MulDiv(100,dpi,96),"controls use actual window DPI");
+            SetWindowPos(settings,nullptr,0,0,480,360,SWP_NOMOVE|SWP_NOZORDER|SWP_NOACTIVATE);
+            SCROLLINFO scroll{sizeof(scroll),SIF_ALL};
+            GetScrollInfo(settings,SB_VERT,&scroll);
+            require(scroll.nMax+1>(int)scroll.nPage,"small settings window has vertical scrolling");
+            GetScrollInfo(settings,SB_HORZ,&scroll);
+            require(scroll.nMax+1>(int)scroll.nPage,"small settings window has horizontal scrolling");
+            SendMessageW(settings,WM_VSCROLL,SB_BOTTOM,0);
+            SendMessageW(settings,WM_HSCROLL,SB_RIGHT,0);
+            GetClientRect(settings,&client);
+            GetWindowRect(GetDlgItem(settings,IDCANCEL),&cancel);
+            MapWindowPoints(nullptr,settings,(POINT*)&cancel,2);
+            require(cancel.left>=0&&cancel.top>=0&&cancel.right<=client.right&&cancel.bottom<=client.bottom,"bottom actions reachable by scrolling");
+            SendMessageW(settings,WM_VSCROLL,SB_TOP,0);
+            SendMessageW(settings,WM_HSCROLL,SB_LEFT,0);
+            SendMessageW(GetDlgItem(settings,IDCANCEL),WM_SETFOCUS,0,0);
+            GetWindowRect(GetDlgItem(settings,IDCANCEL),&cancel);
+            MapWindowPoints(nullptr,settings,(POINT*)&cancel,2);
+            require(cancel.left>=0&&cancel.top>=0&&cancel.right<=client.right&&cancel.bottom<=client.bottom,"keyboard focus reveals off-screen action");
+            SetWindowPos(settings,nullptr,-20000,-20000,0,0,SWP_NOSIZE|SWP_NOZORDER|SWP_NOACTIVATE);
+            SendMessageW(settings,WM_DISPLAYCHANGE,0,0);
+            GetWindowRect(settings,&frame);
+            GetMonitorInfoW(MonitorFromWindow(settings,MONITOR_DEFAULTTONEAREST),&monitor);
+            require(frame.left>=monitor.rcWork.left&&frame.top>=monitor.rcWork.top&&frame.right<=monitor.rcWork.right&&frame.bottom<=monitor.rcWork.bottom,"display change recovers off-screen window");
+            DestroyWindow(settings);
+            DestroyWindow(app.window); app.window=nullptr;
+        }
+        std::filesystem::remove_all(temp);
+        std::cout<<"Passed "<<checks<<" input regression checks\n"; return 0;
+    } catch(const std::exception &e) { std::cerr<<e.what()<<'\n'; return 1; }
+}

tests/integration.cpp

@@ -1,5 +1,7 @@
 #include "app.h"
 #include <iostream>
+#include <fstream>
+#include <commctrl.h>
 
 namespace
 {
@@ -14,6 +16,12 @@ const std::vector<std::pair<std::wstring, std::wstring>> punctuationCases{
     {L"ljvf: ", L"дома: "},   {L"ljvf; ", L"дома; "},   {L"#ljvf%; ", L"#дома%; "}};
 ULONGLONG deadline{};
 std::wstring sentinel = L"KSwitcher integration clipboard sentinel";
+std::string diagnosticLog()
+{
+    std::ifstream file(ks::dataDirectory() / L"kswitcher.log");
+    return {std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>()};
+}
+size_t diagnosticStart{};
 void require(bool ok, const char *name)
 {
     if (!ok)
@@ -109,10 +117,28 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 require(text() == L"OLDпривет", "recent-input conversion preserves adjacent older text");
                 prepare(L"OLDabcdef", false);
                 record(L"ghbdtn");
+                diagnosticStart = diagnosticLog().size();
+                app->busy = true;
+                app->transform(ks::Direct + ru);
+                app->transform(ks::Direct + ru);
+                app->busy = false;
                 app->transform(ks::Direct + ru);
                 break;
             case 6:
                 require(text() == L"OLDabcdef", "recent-input mismatch refuses replacement");
+                {
+                    auto diagnostics = diagnosticLog();
+                    diagnostics = diagnostics.substr(std::min(diagnosticStart, diagnostics.size()));
+                    require(diagnostics.find("reason=busy") != std::string::npos,
+                            "busy conversion attempt is logged");
+                    require(diagnostics.find("repeat=3") != std::string::npos,
+                            "three repeated conversion attempts are logged");
+                    require(diagnostics.find("reason=recent-verification-mismatch") != std::string::npos,
+                            "failed recent-word verification has explicit outcome");
+                    require(diagnostics.find("copied=\"abcdef\"") != std::string::npos &&
+                                diagnostics.find("physicalKeys=\"ghbdtn\"") != std::string::npos,
+                            "conversion diagnostics contain actual text and physical input for reproduction");
+                }
                 app->settings.snippets = {{L";addr", L"LINE1\r\n{cursor}LINE2"}};
                 prepare(L"prefix ;addr", false);
                 record(L";addr");
@@ -237,7 +263,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
     return DefWindowProcW(w, msg, wp, lp);
 }
 } // namespace
-int main()
+int main(int argc, char **argv)
 {
     CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
     auto root = std::filesystem::temp_directory_path() /
@@ -249,6 +275,73 @@ int main()
             app = &instance;
             app->settings.history = false;
             app->settings.switchLayout = false;
+            if (argc > 1 && std::string(argv[1]) == "--logs-only")
+            {
+                ks::showLogs(instance);
+                HWND viewer = instance.logWindow;
+                HWND rows = GetDlgItem(viewer, 602);
+                require(rows && (GetWindowLongPtrW(rows, GWL_STYLE) & LVS_TYPEMASK) == LVS_REPORT,
+                        "log viewer uses report ListView");
+                require(Header_GetItemCount(ListView_GetHeader(rows)) == 4, "log viewer has four columns");
+                require(GetDlgItem(viewer, IDCANCEL) != rows, "log rows and Close have different IDs");
+                SetFocus(rows);
+                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(IDCANCEL, EN_SETFOCUS), (LPARAM)rows);
+                NMHDR clicked{rows, 602, NM_CLICK};
+                SendMessageW(viewer, WM_NOTIFY, 602, (LPARAM)&clicked);
+                require(IsWindow(viewer), "focus and click notifications do not close log viewer");
+                ks::showLogs(instance);
+                require(instance.logWindow == viewer, "opening logs reuses the existing window");
+                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(603, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 603));
+                require(IsWindow(viewer) && ListView_GetItemCount(rows) > 0, "refresh populates log rows");
+                SendDlgItemMessageW(viewer, 601, CB_SETCURSEL, 1, 0);
+                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(601, CBN_SELCHANGE), (LPARAM)GetDlgItem(viewer, 601));
+                require(IsWindow(viewer) && ListView_GetItemCount(rows) > 0, "previous log or empty state is displayed");
+                if (argc > 2 && std::string(argv[2]) == "--clear-test")
+                {
+                    require(std::filesystem::path(ks::executable()).parent_path().filename() == L"log-clear-test",
+                            "clear test runs in isolated executable directory");
+                    const auto logRoot = ks::dataDirectory();
+                    require(logRoot == std::filesystem::path(ks::executable()).parent_path() / L"data",
+                            "clear test uses isolated portable data");
+                    std::ofstream(logRoot / L"kswitcher.log") << "current-marker\n";
+                    std::ofstream(logRoot / L"kswitcher.log.1") << "previous-marker\n";
+                    ks::diagnosticEvent(L"buffered-before-clear");
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(606, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 606));
+                    require(!std::filesystem::exists(logRoot / L"kswitcher.log.1") &&
+                                ks::readDiagnosticLog(false).find(L"current-marker") != std::wstring::npos,
+                            "Clear log removes selected previous log only");
+                    SendDlgItemMessageW(viewer, 601, CB_SETCURSEL, 0, 0);
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(606, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 606));
+                    require(!std::filesystem::exists(logRoot / L"kswitcher.log") && IsWindow(viewer),
+                            "Clear log clears current file without closing viewer");
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(606, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 606));
+                    ks::diagnosticEvent(L"new-problem", true);
+                    auto newLog = ks::readDiagnosticLog(false);
+                    require(newLog.find(L"new-problem") != std::wstring::npos &&
+                                newLog.find(L"buffered-before-clear") == std::wstring::npos,
+                            "logging resumes after clear without stale context");
+                }
+                auto savedClipboard = ks::readClipboard(viewer);
+                instance.window = viewer;
+                try
+                {
+                    ListView_SetItemState(rows, 0, LVIS_SELECTED, LVIS_SELECTED);
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(605, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 605));
+                    require(ks::readClipboard(viewer).text().find(L'\t') != std::wstring::npos,
+                            "selected log row copies as tab-separated columns");
+                }
+                catch (...)
+                {
+                    ks::writeClipboard(viewer, savedClipboard);
+                    throw;
+                }
+                ks::writeClipboard(viewer, savedClipboard);
+                instance.window = nullptr;
+                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(IDCANCEL, BN_CLICKED), (LPARAM)GetDlgItem(viewer, IDCANCEL));
+                require(!IsWindow(viewer) && !instance.logWindow, "Close button closes and releases viewer");
+                CoUninitialize();
+                return 0;
+            }
             for (int i = 0; i < (int)app->layouts.size(); ++i)
             {
                 auto language = LOWORD((uintptr_t)app->layouts[i].handle);

tests/tests.cpp

@@ -44,7 +44,37 @@ int main(int argc, char **argv)
     }
     try
     {
+        require(ks::diagnosticText(L"word") == L"\"word\" units=4 truncated=0",
+                "diagnostic word preserved");
+        require(ks::diagnosticText(L"\"\\\n\r\t") ==
+                    L"\"\\\"\\\\\\u000a\\u000d\\u0009\" units=5 truncated=0",
+                "diagnostic control characters cannot create log lines");
+        require(ks::diagnosticText(L"\u0457\u200b") == L"\"\\u0457\\u200b\" units=2 truncated=0",
+                "diagnostic unicode and invisible characters preserved exactly");
+        require(ks::diagnosticText(std::wstring(513, L'a')).find(L"units=513 truncated=1") != std::wstring::npos,
+                "large diagnostic selections are explicitly truncated");
         STARTUPINFOW startup{sizeof(startup)};
+        ks::DiagnosticBuffer diagnostics;
+        require(diagnostics.record(L"successful-attempt", false, 100).empty(),
+                "successful diagnostics stay in memory");
+        auto incident = diagnostics.record(L"failed-attempt", true, 200);
+        require(incident.find(L"successful-attempt") != std::wstring::npos &&
+                    incident.find(L"failed-attempt") != std::wstring::npos,
+                "incident includes preceding successful context");
+        require(diagnostics.record(L"next-failure", true, 300).find(L"successful-attempt") == std::wstring::npos,
+                "flushed context is not duplicated");
+        diagnostics.record(L"expired-context", false, 400);
+        require(diagnostics.record(L"later-failure", true, 30500).find(L"expired-context") == std::wstring::npos,
+                "context expires after thirty seconds");
+        diagnostics.record(L"oldest-context", false, 30600);
+        for (int i = 0; i < 40; ++i)
+            diagnostics.record(L"bounded-context", false, 30600 + i);
+        require(diagnostics.record(L"bounded-failure", true, 30700).find(L"oldest-context") == std::wstring::npos,
+                "context buffer has a fixed size");
+        diagnostics.record(L"disabled-context", false, 30800);
+        diagnostics.clear();
+        require(diagnostics.record(L"new-failure", true, 30900).find(L"disabled-context") == std::wstring::npos,
+                "clearing diagnostics discards sensitive context");
         startup.dwFlags = STARTF_USESHOWWINDOW;
         startup.wShowWindow = SW_HIDE;
         PROCESS_INFORMATION child{};
@@ -346,6 +376,7 @@ int main(int argc, char **argv)
             require(history.entries().size() == 2, "a new screenshot is retained");
         }
         ks::Settings settings;
+        settings.writeLog = false;
         settings.elevatedAutostart = true;
         settings.autoCorrect = true;
         settings.autoMaxRank = 10000;
@@ -358,6 +389,13 @@ int main(int argc, char **argv)
         settings.snippets = {{L";address", L"Line 1\r\n{cursor}Line 2"}};
         ks::saveSettings(temp / L"settings.json", settings);
         auto restored = ks::loadSettings(temp / L"settings.json", {});
+        require(ks::encodeSettings(ks::decodeSettings(ks::encodeSettings(settings), {})) == ks::encodeSettings(settings),
+                "configurator snapshot survives serialization without changing the concurrency token");
+        rejects([&] { ks::decodeSettings(ks::Bytes{'{', '}'}, {}); },
+                "configurator rejects missing settings format");
+        require(!restored.writeLog, "logging setting persists when disabled");
+        require(ks::loadSettings(temp / L"defaults.json", {}).writeLog,
+                "logging defaults on for existing diagnostic installations");
         require(restored.snippets[0].text == settings.snippets[0].text, "settings snippet roundtrip");
         require(restored.cycle == settings.cycle, "layout order roundtrip");
         require(restored.elevatedAutostart, "elevated autostart setting roundtrip");

tests/update.ps1

@@ -0,0 +1,99 @@
+param([string]$Executable = (Join-Path $PSScriptRoot '../build/KSwitcher.exe'), [switch]$Network)
+$ErrorActionPreference='Stop'
+. (Join-Path $PSScriptRoot '../resources/update.ps1') -Library
+$script:checks=0
+function Assert($Value,[string]$Name) { if (!$Value) { throw $Name }; ++$script:checks }
+function Reject([scriptblock]$Action,[string]$Name) { $rejected=$false; try { & $Action } catch { $rejected=$true }; Assert $rejected $Name }
+$root=Join-Path ([IO.Path]::GetTempPath()) ('KSwitcher-update-tests-'+[guid]::NewGuid().ToString('N'))
+[IO.Directory]::CreateDirectory($root) | Out-Null
+try {
+    $binaryInfo = [Diagnostics.FileVersionInfo]::GetVersionInfo((Resolve-Path -LiteralPath $Executable).Path)
+    $binaryVersion = Get-StableVersion $binaryInfo.FileVersion
+    Assert ($null -ne $binaryVersion) 'executable has a stable version'
+    Assert ($binaryInfo.FileDescription -ceq ('KSwitcher ' + [char]0x2014 + ' native keyboard and clipboard utility')) 'executable description preserves Unicode em dash'
+    Assert ((Get-StableVersion 'v0.10.0') -gt (Get-StableVersion 'v0.2.9')) 'numeric versions'
+    Assert ($null -eq (Get-StableVersion 'v1.0.0-beta')) 'prerelease rejected'
+    Assert ($null -eq (Get-StableVersion 'v1.0.0;whoami')) 'invalid version rejected'
+    $assets=@(
+        @{name='KSwitcher-win-x64.zip';browser_download_url='https://gitea.hrynco.com/hrynco/hrynco-kswitcher/releases/download/v0.2.1/KSwitcher-win-x64.zip'},
+        @{name='SHA256SUMS.txt';browser_download_url='https://gitea.hrynco.com/hrynco/hrynco-kswitcher/releases/download/v0.2.1/SHA256SUMS.txt'}
+    )
+    $release=@{draft=$false;prerelease=$false;tag_name='v0.2.1';assets=$assets}
+    Assert ((Select-Release @($release) ([version]'0.2.0')).version -eq 'v0.2.1') 'newer release'
+    Assert ($null -eq (Select-Release @($release) ([version]'0.2.1'))) 'same version'
+    Assert ($null -eq (Select-Release @($release) ([version]'0.3.0'))) 'no downgrade'
+    $draft=@{draft=$true;prerelease=$false;tag_name='v9.0.0';assets=$assets}
+    Assert ((Select-Release @($draft,$release) ([version]'0.2.0')).version -eq 'v0.2.1') 'draft ignored'
+    Reject { Select-Release @(@{draft=$false;prerelease=$false;tag_name='v2.0.0';assets=@()}) ([version]'0.2.0') } 'incomplete release rejected'
+    foreach ($url in @('http://gitea.hrynco.com/hrynco/hrynco-kswitcher/releases/download/v1/a','https://evil.example/a','https://gitea.hrynco.com/other/a','https://gitea.hrynco.com:8443/hrynco/hrynco-kswitcher/releases/download/v1/a')) {
+        Reject { Assert-ReleaseUrl $url } 'untrusted URL rejected'
+    }
+    $source=Join-Path $root 'source'; [IO.Directory]::CreateDirectory($source) | Out-Null
+    Copy-Item -LiteralPath $Executable -Destination (Join-Path $source 'KSwitcher.exe')
+    $configurator = Join-Path (Split-Path $Executable) 'KSwitcher.Config.exe'
+    if (Test-Path -LiteralPath $configurator) {
+        Copy-Item -LiteralPath $configurator -Destination (Join-Path $source 'KSwitcher.Config.exe')
+    }
+    foreach ($name in @('LICENSE','json-LICENSE.txt','README.md')) { [IO.File]::WriteAllText((Join-Path $source $name),'fixture') }
+    [IO.Directory]::CreateDirectory((Join-Path $source 'dictionaries')) | Out-Null
+    [IO.File]::WriteAllText((Join-Path $source 'dictionaries/en.txt'),'new dictionary')
+    Add-Type -AssemblyName System.IO.Compression.FileSystem
+    $archive=Join-Path $root 'release.zip'
+    [IO.Compression.ZipFile]::CreateFromDirectory($source,$archive)
+    $sum=Join-Path $root 'SHA256SUMS.txt'
+    ((Get-FileHash -LiteralPath $archive -Algorithm SHA256).Hash+'  KSwitcher-win-x64.zip') | Set-Content -LiteralPath $sum
+    Assert-Checksum $archive $sum; ++$script:checks
+    $stage=Join-Path $root 'stage'
+    Expand-Release $archive $stage $binaryVersion; ++$script:checks
+    Reject { Expand-Release $archive (Join-Path $root 'wrong-version') ([version]'9.0.0') } 'version mismatch rejected'
+    ('0'*64+'  KSwitcher-win-x64.zip') | Set-Content -LiteralPath $sum
+    Reject { Assert-Checksum $archive $sum } 'corrupt package rejected'
+    $bad=Join-Path $root 'bad.zip'
+    $z=[IO.Compression.ZipFile]::Open($bad,[IO.Compression.ZipArchiveMode]::Create)
+    $null=$z.CreateEntry('../escape.exe'); $z.Dispose()
+    Reject { Expand-Release $bad (Join-Path $root 'badstage') ([version]'0.2.1') } 'zip traversal rejected'
+    $target=Join-Path $root 'install'; $backup=Join-Path $root 'backup'
+    [IO.Directory]::CreateDirectory((Join-Path $target 'data')) | Out-Null
+    [IO.Directory]::CreateDirectory((Join-Path $target 'dictionaries')) | Out-Null
+    [IO.File]::WriteAllText((Join-Path $target 'data/settings.json'),'personal settings')
+    [IO.File]::WriteAllText((Join-Path $target 'dictionaries/en.txt'),'personal dictionary')
+    [IO.File]::WriteAllText((Join-Path $target 'KSwitcher.exe'),'old binary fixture')
+    $changed=[Collections.Generic.List[string]]::new()
+    Install-Files $stage $target $backup $changed
+    Assert ((Get-FileHash -LiteralPath (Join-Path $target 'KSwitcher.exe')).Hash -eq (Get-FileHash -LiteralPath $Executable).Hash) 'replacement installed'
+    if (Test-Path -LiteralPath $configurator) {
+        Assert ((Get-FileHash -LiteralPath (Join-Path $target 'KSwitcher.Config.exe')).Hash -eq (Get-FileHash -LiteralPath $configurator).Hash) 'configurator installed'
+    }
+    Assert ([IO.File]::ReadAllText((Join-Path $target 'data/settings.json')) -eq 'personal settings') 'settings preserved'
+    Assert ([IO.File]::ReadAllText((Join-Path $target 'dictionaries/en.txt')) -eq 'personal dictionary') 'dictionary preserved'
+    Undo-Files $target $backup $changed
+    Assert ([IO.File]::ReadAllText((Join-Path $target 'KSwitcher.exe')) -eq 'old binary fixture') 'rollback restores original'
+    Assert (!(Test-Path -LiteralPath (Join-Path $target 'README.md'))) 'rollback removes newly introduced files'
+    Assert (!(Test-Path -LiteralPath (Join-Path $target 'KSwitcher.Config.exe'))) 'rollback removes newly introduced configurator'
+    # Fail after the original exe has moved to backup, as if the staged file vanished.
+    $stage2=Join-Path $root 'stage2'; [IO.Directory]::CreateDirectory($stage2) | Out-Null
+    [IO.File]::WriteAllText((Join-Path $stage2 'KSwitcher.exe'),'new binary fixture')
+    $locked=[IO.File]::Open((Join-Path $stage2 'KSwitcher.exe'),[IO.FileMode]::Open,[IO.FileAccess]::Read,[IO.FileShare]::None)
+    $changed2=[Collections.Generic.List[string]]::new()
+    try { Reject { Install-Files $stage2 $target $backup $changed2 } 'locked staged file fails safely' } finally { $locked.Dispose() }
+    Undo-Files $target $backup $changed2
+    Assert ([IO.File]::ReadAllText((Join-Path $target 'KSwitcher.exe')) -eq 'old binary fixture') 'partial install rollback'
+    if ($Network) {
+        $metadata=Join-Path $root 'live-releases.json'
+        Receive-File 'https://gitea.hrynco.com/api/v1/repos/hrynco/hrynco-kswitcher/releases?limit=100' $metadata 2MB
+        $live=Select-Release (Get-Content -LiteralPath $metadata -Raw | ConvertFrom-Json) ([version]'0.0.0')
+        Assert ($null -ne $live) 'live repository exposes a complete stable release'
+        $liveZip=Join-Path $root 'live.zip'; $liveSum=Join-Path $root 'live-sums.txt'
+        Receive-File $live.zip $liveZip 50MB
+        Receive-File $live.checksum $liveSum 64KB
+        Assert-Checksum $liveZip $liveSum; ++$script:checks
+        Expand-Release $liveZip (Join-Path $root 'live-stage') (Get-StableVersion $live.version); ++$script:checks
+        Reject { Receive-File 'https://gitea.hrynco.com/api/v1/repos/hrynco/kswitcher-updater-missing-test-repository' (Join-Path $root 'missing') 2MB } 'server failure reported'
+        Write-Output "Downloaded and validated $($live.version) in a disposable test directory; no application was updated."
+    }
+    Write-Output "Passed $script:checks updater regression checks"
+} finally {
+    if ([IO.Path]::GetDirectoryName($root) -eq [IO.Path]::GetTempPath().TrimEnd('\') -and (Split-Path -Leaf $root) -like 'KSwitcher-update-tests-*') {
+        Remove-Item -LiteralPath $root -Recurse -Force
+    }
+}

tools/update-running-build.ps1

@@ -6,6 +6,9 @@ try {
     $stop = Start-Process -FilePath $exe -ArgumentList '--exit' -WindowStyle Hidden -PassThru
     if (-not $stop.WaitForExit(5000)) { throw 'Exit command timed out.' }
     foreach ($process in $running) { if (-not $process.WaitForExit(10000)) { throw 'KSwitcher did not stop.' } }
+    $config = @(Get-Process 'KSwitcher.Config' -ErrorAction SilentlyContinue | Where-Object { $_.Path -eq (Join-Path $root 'build\KSwitcher.Config.exe') })
+    foreach ($process in $config) { if (-not $process.WaitForExit(10000)) { throw 'Close the configurator before updating.' } }
+    Copy-Item -LiteralPath (Join-Path $root 'build\staged\KSwitcher.Config.exe') -Destination (Join-Path $root 'build\KSwitcher.Config.exe') -Force
     Copy-Item -LiteralPath (Join-Path $root 'build\staged\KSwitcher.exe') -Destination $exe -Force
     Start-Process -FilePath $exe -WindowStyle Hidden
     'OK' | Set-Content -LiteralPath (Join-Path $root 'build\update-result.txt')