Release v0.6.36: offload notification registration and mitigate Viber paste timing

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.24)
-project(KSwitcher VERSION 0.6.29 LANGUAGES CXX RC)
+project(KSwitcher VERSION 0.6.36 LANGUAGES CXX RC)
 if(NOT WIN32)
   message(FATAL_ERROR "KSwitcher uses native Windows APIs")
 endif()
@@ -65,6 +65,15 @@ else()
   target_link_options(KSwitcherOcrTests PRIVATE -static -static-libgcc -static-libstdc++)
 endif()
 enable_testing()
+add_executable(KSwitcherDictionaryTests tests/dictionary.cpp)
+target_link_libraries(KSwitcherDictionaryTests PRIVATE kscore psapi)
+if(MSVC)
+  set_property(TARGET KSwitcherDictionaryTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherDictionaryTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
+add_test(NAME dictionary-regressions COMMAND KSwitcherDictionaryTests)
+set_tests_properties(dictionary-regressions PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 add_test(NAME sync-regressions COMMAND KSwitcherSyncTests)
 add_test(NAME native-regressions COMMAND KSwitcherTests)
 add_test(NAME scroll-regressions COMMAND KSwitcherScrollTests)

README.md

@@ -16,10 +16,15 @@ 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.
+Closing Settings with unsaved changes (including accepted auto-correction or OCR options)
+asks whether to save, discard changes, or keep editing. Unchanged settings close without a prompt.
+If saving fails, the window stays open with your edits intact.
 Menus support access keys: press the underlined letter while the menu is open (for example,
 S for Settings or X for Exit in the tray menu). In forms, press Alt+the underlined letter
-to activate a button, toggle a checkbox or focus a labeled field. Press Alt to reveal
+to activate a button, toggle a checkbox or focus a labeled field. Dialog underline visibility
-the underlines when Windows hides them. Shortcut-capture fields still record Alt combinations;
+still follows Windows preferences; press Alt in a dialog to reveal them.
+From v0.6.33, tray and history menus show access letters in the right-hand column.
+Press the menu letter without Alt: Alt dismisses an open menu. Shortcut-capture fields still record Alt combinations;
 press Tab to leave a shortcut field before using form access keys.
 Settings, the snippet editor and log viewer run on demand in **KSwitcher.Config.exe**, beside the main executable.
 Repeated launches activate the existing configurator; closing its last window exits that process.
@@ -170,7 +175,8 @@ for shapes.
 **Canvas zoom:** use **Ctrl++ / Ctrl+-** (including numpad keys) or **Ctrl+mouse wheel**.
 Each step changes the view by 25%; the wheel zooms around the cursor, keyboard shortcuts around
 the viewport center. **Ctrl+0** restores the initial fit. Drag with the **middle mouse button**
-to pan an enlarged image. Zoom ranges from 0.1× to 16× the initial fit; the status bar shows the
+to pan an enlarged image. Panning is limited to axes where the image exceeds the viewport;
+an image that fits stays centered. Zoom ranges from 0.1× to 16× the initial fit; the status bar shows the
 actual image scale. Zoom and pan do not change annotations, export resolution or undo history.
 The wheel without Ctrl still adjusts the object under the cursor.
 
@@ -186,6 +192,9 @@ Every shape has a round rotation handle above its outline. Drag it to rotate aro
 hold **Shift** for 15-degree steps. The handle works for toolbar shapes and recognized shapes,
 including triangles. Resize handles and attached connectors follow the rotation; Ctrl+Z/Ctrl+Y
 undo and redo it. The square handle still controls outline thickness.
+From v0.6.34, endpoint, shape-corner and number-radius handles show the four-direction move cursor.
+Thickness handles retain directional resize cursors; rotation retains the hand cursor. Dragging,
+snapping and shape constraints are unchanged.
 **Triangle (G)** is also available directly on the toolbar: drag to create a triangle.
 Both drawn and recognized triangles have three independent vertex handles instead of bounding-box
 resize handles. Drag any vertex to reshape the triangle while keeping the other two fixed, even
@@ -271,7 +280,11 @@ thumbnails and source labels aligned with the scaled fonts and spacing.
 - Clipboard snapshot/restoration with concurrent-copy, foreground and input-version checks.
   A silently dropped copy is retried up to three total attempts while the clipboard and input
   context remain unchanged. Temporary transaction contents are excluded from Windows clipboard
-  history and cloud synchronization. Paste is not blindly retried.
+  history and cloud synchronization. Paste is not blindly retried: with manual paste readback
+  enabled by Write log, a native Windows EDIT gets at most one retry when readback reports the
+  original and fresh native queries confirm that exactly the original range is still selected.
+  Other controls and unknown/changed selections are not retried. A verified failed paste clears
+  repeat-conversion state and does not switch the Windows layout.
 - Case cycling, Russian/Ukrainian transliteration, verified undo and repeated conversion.
 - Text snippets across layouts, multiline insertion and a verified `{cursor}` position;
   `{enter}` presses Enter after insertion and cursor placement (once per marker), before buffered typing resumes.
@@ -614,7 +627,12 @@ support automatic correction. Dictionary recognition is heuristic, not an unders
 subtitle vocabulary is incomplete, and uncommon names or jargon can need personal exceptions.
 
 No network service or language model is used. The three dictionary files occupy about 2.6 MB on disk;
-the English/Ukrainian lookup data uses less than 3 MiB of RAM and is loaded on first automatic check.
+the bundled EN/UK/RU lookup payload uses about 0.90 MiB of RAM. When automatic correction is enabled,
+selected dictionaries are loaded before typing and shared by the input predictor and worker.
+Words are stored in compact indexed blocks; all words and frequency ranks are retained, and editable
+UTF-8 dictionary files keep the same format. Custom dictionaries can use more memory.
+`build.ps1 -Test` checks every bundled word/rank and measures lookup speed; CMake exposes the same
+check as `dictionary-regressions`. The payload figure excludes the rest of the process and allocator overhead.
 Keep `dictionaries/` beside the executable when copying the app. These word lists derive from
 [FrequencyWords](https://github.com/hermitdave/FrequencyWords) and are separately licensed under
 CC BY-SA 4.0; attribution, pinned source revision and license are in `dictionaries/`.
@@ -685,3 +703,11 @@ Keep `v0.4.2` as the last legacy `vX.Y.Z` release. Publish full packages as
 legacy version tag: clients that have not installed the bridge would select it.
 Keep the compatibility bridge in the first 100 releases returned by Gitea while
 supporting old clients; their immutable update code only reads that page.
+
+### Editors that omit copied trailing spaces
+
+From v0.6.31, KSwitcher recovers trailing ordinary spaces omitted by Ctrl+C only when Windows accessibility proves the complete selection. The same focused control and range are rechecked before paste, and the result is read back even without Write log. Recent-text conversion, automatic correction, repeat conversion and Undo retain exact verification. Missing letters, tabs, line breaks and unavailable or ambiguous selections are not reconstructed. No setting or shortcut has changed.
+
+### Notification registration and Viber — v0.6.36
+
+Notification registration runs in KSwitcher.Screenshot.exe; keep all three executables together. Startup registration is asynchronous. Viber pastes allow 75 ms for clipboard notifications before Ctrl+V, retaining focus, ownership and selection checks. This mitigates an intermittent clipboard timing issue; it does not guarantee all Viber failures are resolved. UI Automation is unchanged.

Release/README.md

@@ -1,29 +1,22 @@
 # Latest Windows release
 
-## v0.6.29 — 2026-11-02
+## v0.6.36 — 2026-11-04
 
 ## Changes
-- Added **Clear history… / Alt+H** directly to the Clipboard history window beside Edit image / Open item.
+- Notification registration now runs in the existing KSwitcher.Screenshot.exe helper. Startup launches it asynchronously and checks its exit status without blocking keyboard work; update notification registration waits in its background worker. Keep all three executables together. UI Automation and notification activation routes remain unchanged.
-- Clearing requires confirmation, with **No** selected by default. It removes all saved entries, including pinned entries and entries hidden by the current search. Cancelling leaves history unchanged.
+- Viber paste now allows 75 ms for clipboard notifications to settle before sending Ctrl+V, then rechecks input, focus and clipboard ownership. This mitigates a suspected clipboard timing race: an intermittent corrupted Cyrillic paste was reproduced on the prior build. It is not a guarantee that every Viber timing issue is resolved; no blind paste retries or relaxed selection checks were added.
-- The button follows the existing bottom action row when resizing. Settings retains its existing Clear history action.
+- Added regression coverage for an explicitly selected middle range followed by a repeated shortcut without selection, preserving surrounding text, trailing spaces and the original clipboard. Updated the integration fixture to initialize shared predictor dictionaries.
-- Clearing saved history does not clear the current Windows clipboard or disable future recording. This release does not change memory management.
+- Added reproducible standalone COM, UI Automation and Shell memory measurement tools. No shortcuts, settings or defaults changed.
 
 ## Validation
-The final build passed isolated checks for the new button, cancellation, confirmed deletion of pinned/search-hidden entries and persistence after reloading the history store. 48 updater regression checks passed; all executable versions and release-manifest hashes were verified. The full desktop-interaction suite was not rerun for this focused patch.
+Full staged build and tests cover dictionary equivalence for all 140,939 words, 105 sync checks, wheel batching, 304 native checks, 559 input checks, screenshot UI/PNG/registration, 48 updater checks and updater progress UI. Conversion integration passed 43 assertions. Eight actual Viber conversions passed on the development build, including two complete long-text layout cycles and selected/repeated middle-word conversion; test messages were not sent.
 
-## Known limitations
+A controlled fresh-launch before/after comparison (five private-working-set samples each, same installation and settings) measured 4.69 → 4.18 MiB, about 0.51 MiB saved. This is one local comparison, not a fixed memory limit or a long-term idle guarantee. The prior compact dictionaries and cache/idle memory reductions remain included.
-Existing asynchronous-editor selection/clipboard limitations remain; this release does not fix the reported ChatGPT selection mismatch. Dictionary typo correction and OpenBao synchronization remain experimental as documented in v0.6.28.
 
-**Upgrade:** choose Update in the tray menu. Legacy v0.3.0–v0.4.1 clients first receive the v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.
+## Upgrade
+Choose **Update** in the tray menu. Legacy v0.3.0–v0.4.1 clients first receive the v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.
 For manual installation, exit KSwitcher, close screenshot editors and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.
 
-Download **KSwitcher-win-x64.zip** with **SHA256SUMS.txt**. The package includes all three executables, a release manifest, offline dictionaries, documentation and license notices. No personal settings, passwords, server address or clipboard history are included.
+Download **KSwitcher-win-x64.zip** with **SHA256SUMS.txt**. Keep all three executables together. The package contains no personal settings, credentials or clipboard history.
-
-Build and package:
-
-```powershell
-.\build.ps1 -Stage -Test
-.\package.ps1 -PublishRelease
-```
 
 Publish stable `release-vX.Y.Z` tags matching the executable version. Keep `v0.4.2` as the last legacy tag.

Release/SHA256SUMS.txt

@@ -1 +1 @@
-c9c3e3579575a41d434201d4f37bf3829e53c1ef23c42cb1c077930dfe8fdfa6  KSwitcher-win-x64.zip
+794d74113bddf13ffee7317cadee9c472bca3b84b3361796db58ff8023f66571  KSwitcher-win-x64.zip

build.ps1

@@ -41,6 +41,10 @@ try {
     if ($LASTEXITCODE) { throw 'Screenshot link failed' }
     Copy-Item -LiteralPath $screenshotPath -Destination build/release/KSwitcher.Screenshot.exe -Force
     if ($Test) {
+        & $compiler @common tests/dictionary.cpp build/core.o build/platform.o build/autocorrect.o @libs -lpsapi -static -s -o build/KSwitcherDictionaryTests.exe
+        if ($LASTEXITCODE) { throw 'Dictionary test build failed' }
+        & .\build\KSwitcherDictionaryTests.exe
+        if ($LASTEXITCODE) { throw 'Dictionary tests failed' }
         & $compiler @common tests/sync.cpp build/core.o build/platform.o build/storage.o build/sync.o build/ocr.o @libs -static -s -o build/KSwitcherSyncTests.exe
         if ($LASTEXITCODE) { throw 'Sync test build failed' }
         & .\build\KSwitcherSyncTests.exe

resources/app.rc

@@ -9,8 +9,8 @@ IDC_SCREENSHOT_PENCIL CURSOR "icons/lucide/pencil.cur"
 1 RT_MANIFEST "app.manifest"
 201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,6,29,0
+ FILEVERSION 0,6,36,0
- PRODUCTVERSION 0,6,29,0
+ PRODUCTVERSION 0,6,36,0
  FILEOS VOS_NT_WINDOWS32
  FILETYPE VFT_APP
 BEGIN
@@ -20,7 +20,7 @@ BEGIN
   BEGIN
    VALUE "FileDescription", "KSwitcher — native keyboard and clipboard utility"
    VALUE "ProductName", "KSwitcher"
-   VALUE "FileVersion", "0.6.29"
+   VALUE "FileVersion", "0.6.36"
   END
  END
  BLOCK "VarFileInfo"

src/app.cpp

@@ -1,4 +1,5 @@
 #include "app.h"
+#include <utility>
 #include "../vendor/json.hpp"
 #include "../resources/resource.h"
 #include "ocr.h"
@@ -76,6 +77,8 @@ class Transaction
     mutable bool invalidLogged{};
     unsigned copyNumber{};
     std::wstring adopted;
+    std::unique_ptr<PasteProbe> selectionProof;
+    std::wstring provenSelection;
 
   public:
     Transaction(App &a, HWND t, uint64_t v) : app(a), target(t), version(v)
@@ -250,8 +253,27 @@ class Transaction
                 }
             }
         }
+        selectionProof.reset();
+        provenSelection.clear();
+        // Viber and some other editors omit trailing ASCII spaces from Ctrl+C.
+        // Recover only from a real selection, never from the recorded keys alone.
+        if (valid() && !text.empty() && text.size() < 8192 && text.back() != L' ')
+        {
+            auto proof = std::make_unique<PasteProbe>(true, target);
+            auto selected = proof->read(1, false);
+            if (selected && selected->size() > text.size() && selected->starts_with(text) &&
+                selected->find_first_not_of(L' ', text.size()) == std::wstring::npos && valid())
+            {
+                diagnosticEvent(L"Copy: trailing spaces verified via accessibility copied=" +
+                    diagnosticText(text) + L" selected=" + diagnosticText(*selected));
+                text = *selected;
+                provenSelection = text;
+                selectionProof = std::move(proof);
+            }
+        }
         return text;
     }
+    bool recoveredSelection() const { return selectionProof != nullptr; }
     bool select(size_t n)
     {
         return selectPrevious(n, [&] { return valid(); });
@@ -324,9 +346,26 @@ class Transaction
     }
     bool paste(const Clip &clip)
     {
+        if (selectionProof)
+        {
+            auto selected = selectionProof->read(1, false);
+            if (!selected || *selected != provenSelection || !valid())
+            {
+                diagnosticEvent(L"Paste cancelled: recovered selection changed or unavailable");
+                return false;
+            }
+        }
         if (!valid())
             return false;
         write(clip);
+        // Viber's Qt editor observes clipboard changes asynchronously. Give it
+        // a chance to discard the data object from Ctrl+C before requesting paste.
+        // Recheck ownership and input below; never retry a possibly applied paste.
+        if (lower(processName(target)) == L"viber")
+        {
+            Sleep(75);
+            diagnosticEvent(L"Paste: Viber clipboard notification settling interval completed");
+        }
         for (int i = 0; i < 2; ++i)
         {
             check();
@@ -338,6 +377,32 @@ class Transaction
         Sleep(300);
         return true;
     }
+    bool nativeSelectionIs(const std::wstring &original) const
+    {
+        if (!valid()) return false;
+        GUITHREADINFO gui{sizeof(gui)};
+        if (!GetGUIThreadInfo(GetWindowThreadProcessId(target, nullptr), &gui) || !gui.hwndFocus) return false;
+        wchar_t cls[32]{};
+        GetClassNameW(gui.hwndFocus, cls, 32);
+        if (_wcsicmp(cls, L"Edit") != 0 ||
+            (GetWindowLongPtrW(gui.hwndFocus, GWL_STYLE) & (ES_PASSWORD | ES_READONLY))) return false;
+        auto query = [&](UINT message, WPARAM wp, LPARAM lp, DWORD_PTR &result)
+        {
+            return SendMessageTimeoutW(gui.hwndFocus, message, wp, lp,
+                                       SMTO_ABORTIFHUNG | SMTO_BLOCK, 100, &result) != 0;
+        };
+        DWORD_PTR range{}, length{}, copied{};
+        if (!query(EM_GETSEL, 0, 0, range) || (DWORD)range == 0xffffffff ||
+            size_t(HIWORD(range) - LOWORD(range)) != original.size() ||
+            !query(WM_GETTEXTLENGTH, 0, 0, length) || length > 65534 || HIWORD(range) > length) return false;
+        std::wstring content(length + 1, L'\0');
+        if (!query(WM_GETTEXT, content.size(), (LPARAM)content.data(), copied) || copied != length) return false;
+        DWORD_PTR after{};
+        GUITHREADINFO focused{sizeof(focused)};
+        return query(EM_GETSEL, 0, 0, after) && after == range && valid() &&
+               GetGUIThreadInfo(GetWindowThreadProcessId(target, nullptr), &focused) && focused.hwndFocus == gui.hwndFocus &&
+               content.substr(LOWORD(range), original.size()) == original;
+    }
 };
 } // namespace
 App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instance(h), smoke(test)
@@ -376,6 +441,7 @@ App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instan
 }
 App::~App()
 {
+    if (notificationRegistration) CloseHandle(notificationRegistration);
     if (syncWorker.joinable()) syncWorker.join();
     if (updateWorker.joinable())
         updateWorker.join();
@@ -586,7 +652,7 @@ void App::applySettings(const Settings &requested)
         ++inputVersion;
         if (busy) diagnosticEvent(L"Input context changed: settings applied version=" + std::to_wstring(inputVersion.load()));
     }
-    // Clear on the worker so the next check reloads edits to dictionary files.
+    // Release the worker's old snapshot; the next check shares the freshly loaded predictor.
     enqueue([this] { autoCorrector.configure({}, {}); });
     scheduleHistoryOcr(s);
     nextSync = std::max(GetTickCount64() + 2000, syncRetryAfter);
@@ -647,6 +713,13 @@ void App::resetInput()
     run.reset();
     last.reset();
 }
+void App::releaseIdleMemory(ULONGLONG now)
+{
+    expireDiagnostics(now);
+    std::lock_guard lock(stateMutex);
+    // Match the Undo eligibility deadline; never discard an available operation.
+    if (!busy && last && now - last->at > 120000) last.reset();
+}
 void App::clearLog(bool previous) { clearDiagnosticLog(previous); }
 void App::keyboard(const KBDLLHOOKSTRUCT &k, UINT mods)
 {
@@ -1110,9 +1183,11 @@ void App::transform(int command, int snippet)
                     if (!config.autoCorrect || recent.window != target || recent.overflow ||
                         recent.keys.empty() || recent.keys.back() != L' ' || hint < 0)
                         return;
-                    autoCorrector.configure(std::filesystem::path(executable()).parent_path() /
+                    {
-                                                L"dictionaries",
+                        std::lock_guard lock(stateMutex);
-                                            config.autoLanguages);
+                        if (inputVersion.load() != version) return;
+                        autoCorrector.shareDictionaries(autoPredictor);
+                    }
                     std::wstring predicted;
                     for (wchar_t key : recent.keys)
                         predicted += key == L' ' ? L' ' : available[hint].at(physicalLayout().code(key));
@@ -1263,6 +1338,11 @@ void App::transform(int command, int snippet)
                         actual = text;
                         verification = L"selection-mismatch";
                         reason = L"previous-result-verification-mismatch";
+                        {
+                            std::lock_guard lock(stateMutex);
+                            last.reset();
+                            run.reset();
+                        }
                         if (tx.valid())
                             chord(VK_RIGHT);
                         return;
@@ -1310,13 +1390,30 @@ void App::transform(int command, int snippet)
                     }
                 }
                 bool sent = false;
-                PasteProbe probe(config.writeLog && manual && result != text, text);
+                const bool requireReadback = tx.recoveredSelection();
+                PasteProbe probe(((config.writeLog && manual) || requireReadback) && result != text, text, target);
+                if (requireReadback && result != text && probe.status != L"ready")
+                {
+                    reason = L"recovered-selection-unavailable";
+                    std::lock_guard lock(stateMutex);
+                    last.reset();
+                    run.reset();
+                    return;
+                }
                 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);
+                if (requireReadback && result != text && !sent)
+                {
+                    reason = L"recovered-selection-paste-cancelled";
+                    std::lock_guard lock(stateMutex);
+                    last.reset();
+                    run.reset();
+                    return;
+                }
                 if (sent || result == text)
                     autoSelected = false;
                 reason = result == text ? L"conversion-unchanged" :
@@ -1326,19 +1423,48 @@ void App::transform(int command, int snippet)
                     reason = L"Conversion unchanged";
                     verification = L"calculated-result-equals-original";
                 }
-                if (sent && manual && config.writeLog)
+                if (sent && ((manual && config.writeLog) || requireReadback))
                 {
                     verification = probe.status;
                     if (tx.valid())
                     {
                         auto observed = probe.read((int)caretSteps(result));
+                        // A native Edit may silently ignore Ctrl+V while the clipboard is busy.
+                        // Retry once only with fresh native proof that the exact original range
+                        // is still selected. Never retry an unknown or changed editor state.
+                        if (observed && newlines(*observed) == newlines(text) && tx.nativeSelectionIs(text))
+                        {
+                            diagnosticEvent(L"Paste retry: native Edit still selects the unchanged original");
+                            if (tx.paste(textClip(result)) && tx.valid())
+                                observed = probe.read((int)caretSteps(result));
+                            else
+                                observed.reset();
+                        }
                         verification = probe.status;
                         if (observed && tx.valid())
                         {
                             actual = *observed;
                             reason = conversionReadbackOutcome(newlines(actual), newlines(text), newlines(result));
+                            if (newlines(actual) != newlines(result))
+                            {
+                                std::lock_guard lock(stateMutex);
+                                last.reset();
+                                run.reset();
+                                diagnosticEvent(L"Paste rejected by readback: previous result cleared; layout not switched");
+                                return;
+                            }
+                        }
+                        else
+                        {
+                            reason = L"Paste not verified";
+                            if (requireReadback)
+                            {
+                                std::lock_guard lock(stateMutex);
+                                last.reset();
+                                run.reset();
+                                return;
+                            }
                         }
-                        else reason = L"Paste not verified";
                     }
                     else verification = L"context-changed-after-paste";
                 }
@@ -1547,6 +1673,7 @@ void App::trayMenu()
     GetCursorPos(&pt);
     pasteTarget = GetForegroundWindow();
     SetForegroundWindow(window);
+    showMenuAccessKeys(menu);
     int cmd = TrackPopupMenu(menu, TPM_RETURNCMD | TPM_RIGHTBUTTON, pt.x, pt.y, 0, window, nullptr);
     DestroyMenu(menu);
     PostMessageW(window, WM_NULL, 0, 0);
@@ -1775,6 +1902,15 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
     case WM_TIMER:
         if (wp == 6)
         {
+            if (app->notificationRegistration && WaitForSingleObject(app->notificationRegistration, 0) == WAIT_OBJECT_0)
+            {
+                DWORD code = ERROR_GEN_FAILURE;
+                GetExitCodeProcess(app->notificationRegistration, &code);
+                if (code) log(L"Screenshot notification registration helper failed: " + std::to_wstring(code));
+                CloseHandle(app->notificationRegistration);
+                app->notificationRegistration = nullptr;
+            }
+            app->releaseIdleMemory(GetTickCount64());
             app->pollSync();
             return 0;
         }
@@ -1893,7 +2029,7 @@ int App::execute()
         log(std::wstring(L"Update completed; running version ") + AppVersion);
     if (startCommand)
         PostMessageW(window, WM_HOTKEY, startCommand, 0);
-    try { registerScreenshotNotifications(); }
+    try { notificationRegistration = startScreenshotNotificationRegistration(); }
     catch(const std::exception &e) { log(L"Screenshot notification registration: "+wide(e.what())); }
     auto screenshotActivation=startScreenshotActivationListener();
     MSG msg;

src/app.h

@@ -86,11 +86,13 @@ class App
 
   private:
     friend struct InputRegressionAccess;
+    void releaseIdleMemory(ULONGLONG now);
     HHOOK keyboardHook{}, mouseHook{};
     std::mutex jobsMutex;
     std::condition_variable jobsReady;
     std::deque<std::function<void()>> jobs;
     std::thread worker;
+    HANDLE notificationRegistration{};
     std::thread historySearchWorker;
     std::condition_variable historySearchReady;
     std::function<void()> pendingHistorySearch;

src/app_sync.inl

@@ -46,7 +46,7 @@ std::wstring App::syncCommand(int action, const std::vector<SyncChoice> &choices
             syncDone.store(true);
         });
     }
-    catch (...) { syncRunning = false; throw; }
+    catch (...) { syncRunning = false; Bytes().swap(syncSnapshot); syncResult = {}; throw; }
     return syncStatus;
 }
 void App::pollSync()
@@ -57,25 +57,28 @@ void App::pollSync()
         {
             if (busy) return;
             syncWorker.join();
+            // Own completed payloads locally so every return/exception releases them.
+            auto result = std::exchange(syncResult, SyncResult{});
+            auto snapshot = std::exchange(syncSnapshot, Bytes{});
             syncRunning = false;
             syncDone = false;
-            syncStatus = syncResult.status;
+            syncStatus = result.status;
-            if (syncResult.success)
+            if (result.success)
             {
-                if (loadSyncConfig(data) != syncConnection || encodeSettings(settings) != syncSnapshot)
+                if (loadSyncConfig(data) != syncConnection || encodeSettings(settings) != snapshot)
                 {
                     syncStatus = L"Local settings or connection changed during sync. Checking again shortly.";
                     nextSync = GetTickCount64() + 2000;
                     return;
                 }
-                auto next = restoreSyncSettings(syncResult.settings, settings, layouts, syncConnection.keepLocalLayouts);
+                auto next = restoreSyncSettings(result.settings, settings, layouts, syncConnection.keepLocalLayouts);
-                if (encodeSettings(next) != syncSnapshot)
+                if (encodeSettings(next) != snapshot)
                 {
-                    atomicWrite(data / L"settings-before-sync.bin", protect(syncSnapshot));
+                    atomicWrite(data / L"settings-before-sync.bin", protect(snapshot));
                     applySettings(next);
                 }
-                saveSyncBase(data, syncConnection, syncResult.base.empty() ? syncResult.settings : syncResult.base);
+                saveSyncBase(data, syncConnection, result.base.empty() ? result.settings : result.base);
-                pendingSyncConflicts = syncResult.conflicts;
+                pendingSyncConflicts = std::move(result.conflicts);
                 conflictConnection = syncConnection;
                 SYSTEMTIME time{}; GetLocalTime(&time);
                 wchar_t stamp[32]{};
@@ -84,8 +87,8 @@ void App::pollSync()
             }
             // Back off after errors (including bad credentials) instead of repeatedly
             // hitting userpass lockout. The explicit Sync button remains available.
-            syncRetryAfter = syncResult.success ? 0 : GetTickCount64() + 15 * 60000;
+            syncRetryAfter = result.success ? 0 : GetTickCount64() + 15 * 60000;
-            nextSync = syncResult.success ? GetTickCount64() + SyncIntervalMs : syncRetryAfter;
+            nextSync = result.success ? GetTickCount64() + SyncIntervalMs : syncRetryAfter;
         }
         if (!syncRunning && GetTickCount64() >= nextSync)
         {

src/autocorrect.cpp

@@ -42,82 +42,160 @@ bool safeAutoWord(const std::wstring &word, int minimumLength)
     auto small = lower(word);
     return word == small || (word.substr(1) == small.substr(1) && word != upper(word));
 }
-std::string_view AutoCorrector::Dictionary::word(size_t index) const
+namespace {
+constexpr size_t DictionaryBlockWords = 32;
+}
+std::string_view AutoCorrector::Dictionary::word(size_t block) const
 {
-    auto start = offsets[index];
+    size_t start = offsets[block];
-    auto end = bytes.find('\t', start);
+    // Every block starts with a complete word (zero shared prefix).
-    return std::string_view(bytes).substr(start, end - start);
+    size_t length = static_cast<unsigned char>(bytes[start++]) & 15;
+    if (length == 15) length = static_cast<unsigned char>(bytes[start++]);
+    return std::string_view(bytes).substr(start, length);
 }
 AutoCorrector::Dictionary::Dictionary(const std::filesystem::path &path)
 {
-    auto raw = readFile(path, 2 * 1024 * 1024);
+    const auto raw = readFile(path, 2 * 1024 * 1024);
-    bytes.assign(raw.begin(), raw.end());
+    const std::string_view source(reinterpret_cast<const char *>(raw.data()), raw.size());
-    for (size_t start = 0; start < bytes.size();)
+    std::vector<uint32_t> lines;
+    lines.reserve(std::count(source.begin(), source.end(), '\n') + 1);
+    for (size_t start = 0; start < source.size();)
     {
-        auto end = bytes.find('\n', start);
+        auto end = source.find('\n', start);
-        if (end == bytes.npos)
+        if (end == source.npos) end = source.size();
-            end = bytes.size();
+        auto tab = source.find('\t', start);
-        auto tab = bytes.find('\t', start);
+        if (tab == source.npos || tab >= end || tab == start || tab - start > 160)
-        if (tab == bytes.npos || tab >= end || tab == start || tab - start > 160)
             throw std::runtime_error("Invalid auto-correction dictionary");
         int rank{};
-        auto rankEnd = end > tab + 1 && bytes[end - 1] == '\r' ? end - 1 : end;
+        auto rankEnd = end > tab + 1 && source[end - 1] == '\r' ? end - 1 : end;
-        auto parse = std::from_chars(bytes.data() + tab + 1, bytes.data() + rankEnd, rank);
+        auto parse = std::from_chars(source.data() + tab + 1, source.data() + rankEnd, rank);
-        if (parse.ec != std::errc() || parse.ptr != bytes.data() + rankEnd || rank <= 0)
+        if (parse.ec != std::errc() || parse.ptr != source.data() + rankEnd || rank <= 0)
             throw std::runtime_error("Invalid dictionary rank");
-        offsets.push_back((uint32_t)start);
+        lines.push_back(static_cast<uint32_t>(start));
         start = end + 1;
     }
-    if (offsets.empty())
+    if (lines.empty()) throw std::runtime_error("Empty auto-correction dictionary");
-        throw std::runtime_error("Empty auto-correction dictionary");
+    auto entry = [&](uint32_t offset) { return source.substr(offset, source.find('\t', offset) - offset); };
-    auto entry = [&](uint32_t offset) { return std::string_view(bytes).substr(offset, bytes.find('\t', offset) - offset); };
+    auto frequency = [&](uint32_t offset) {
-    auto frequency = [&](uint32_t offset)
-    {
         int rank{};
         auto start = offset + entry(offset).size() + 1;
-        std::from_chars(bytes.data() + start, bytes.data() + bytes.size(), rank);
+        std::from_chars(source.data() + start, source.data() + source.size(), rank);
         return rank;
     };
-    std::sort(offsets.begin(), offsets.end(), [&](uint32_t a, uint32_t b)
+    std::sort(lines.begin(), lines.end(), [&](uint32_t a, uint32_t b) {
-              { return entry(a) == entry(b) ? frequency(a) < frequency(b) : entry(a) < entry(b); });
+        return entry(a) == entry(b) ? frequency(a) < frequency(b) : entry(a) < entry(b);
-    offsets.erase(std::unique(offsets.begin(), offsets.end(), [&](uint32_t a, uint32_t b)
+    });
-                              { return entry(a) == entry(b); }), offsets.end());
+    lines.erase(std::unique(lines.begin(), lines.end(), [&](uint32_t a, uint32_t b) {
-    offsets.shrink_to_fit();
+        return entry(a) == entry(b);
-    bytes.shrink_to_fit();
+    }), lines.end());
+    offsets.reserve((lines.size() + DictionaryBlockWords - 1) / DictionaryBlockWords);
+    std::string_view previous;
+    // Allocate the packed payload exactly once. Geometric growth and a final
+    // shrink otherwise leave discarded buffers in the resident process heap.
+    size_t packedSize = 0;
+    for (size_t i = 0; i < lines.size(); ++i)
+    {
+        auto current = entry(lines[i]);
+        size_t prefix = 0;
+        if (i % DictionaryBlockWords != 0)
+            while (prefix < std::min(previous.size(), current.size()) && previous[prefix] == current[prefix]) ++prefix;
+        auto suffix = current.size() - prefix;
+        packedSize += 1 + (prefix >= 15) + (suffix >= 15) + suffix + 2;
+        auto rank = static_cast<uint32_t>(frequency(lines[i]));
+        if (rank >= 65535)
+            do { ++packedSize; rank >>= 7; } while (rank);
+        previous = current;
+    }
+    bytes.reserve(packedSize);
+    previous = {};
+    for (size_t i = 0; i < lines.size(); ++i)
+    {
+        auto current = entry(lines[i]);
+        size_t prefix = 0;
+        if (i % DictionaryBlockWords == 0)
+            offsets.push_back(static_cast<uint32_t>(bytes.size()));
+        else
+            while (prefix < std::min(previous.size(), current.size()) && previous[prefix] == current[prefix]) ++prefix;
+        size_t suffix = current.size() - prefix;
+        bytes.push_back(static_cast<char>((std::min(prefix, size_t(15)) << 4) | std::min(suffix, size_t(15))));
+        if (prefix >= 15) bytes.push_back(static_cast<char>(prefix));
+        if (suffix >= 15) bytes.push_back(static_cast<char>(suffix));
+        bytes.append(current.substr(prefix));
+        auto rank = static_cast<uint32_t>(frequency(lines[i]));
+        auto shortRank = std::min(rank, uint32_t(65535));
+        bytes.push_back(static_cast<char>(shortRank & 255));
+        bytes.push_back(static_cast<char>(shortRank >> 8));
+        if (rank >= 65535)
+            do {
+                auto next = rank & 127;
+                rank >>= 7;
+                bytes.push_back(static_cast<char>(next | (rank ? 128 : 0)));
+            } while (rank);
+        previous = current;
+    }
 }
 int AutoCorrector::Dictionary::rank(const std::wstring &text) const
 {
     auto key = utf8(lower(text));
     size_t begin = 0, end = offsets.size();
+    // Find the last block whose first word is <= the search key.
     while (begin < end)
     {
         auto mid = begin + (end - begin) / 2;
-        if (word(mid) < key)
+        if (word(mid) <= key) begin = mid + 1;
-            begin = mid + 1;
+        else end = mid;
-        else
-            end = mid;
     }
-    if (begin == offsets.size() || word(begin) != key)
+    if (!begin) return 0;
-        return 0;
+    size_t block = begin - 1;
-    auto start = offsets[begin] + word(begin).size() + 1;
+    size_t at = offsets[block];
-    int rank{};
+    const size_t limit = begin < offsets.size() ? offsets[begin] : bytes.size();
-    std::from_chars(bytes.data() + start, bytes.data() + bytes.size(), rank);
+    char decoded[160]; // The loader validates lengths; lookup never allocates a decoded word.
-    return rank;
+    while (at < limit)
+    {
+        auto lengths = static_cast<unsigned char>(bytes[at++]);
+        size_t prefix = lengths >> 4, suffix = lengths & 15;
+        if (prefix == 15) prefix = static_cast<unsigned char>(bytes[at++]);
+        if (suffix == 15) suffix = static_cast<unsigned char>(bytes[at++]);
+        memcpy(decoded + prefix, bytes.data() + at, suffix);
+        at += suffix;
+        uint32_t rank = static_cast<unsigned char>(bytes[at]) |
+                        (uint32_t(static_cast<unsigned char>(bytes[at + 1])) << 8);
+        at += 2;
+        if (rank == 65535) {
+            rank = 0;
+            uint32_t shift = 0;
+            unsigned char part;
+            do {
+                part = static_cast<unsigned char>(bytes[at++]);
+                rank |= uint32_t(part & 127) << shift;
+                shift += 7;
+            } while (part & 128);
+        }
+        auto compared = std::string_view(decoded, size_t(prefix) + suffix).compare(key);
+        if (compared == 0) return static_cast<int>(rank);
+        if (compared > 0) return 0;
+    }
+    return 0;
 }
 void AutoCorrector::configure(const std::filesystem::path &folder, const std::vector<std::wstring> &wanted)
 {
     if (languages == wanted)
         return;
-    std::map<std::wstring, Dictionary> next;
+    std::map<std::wstring, std::shared_ptr<const Dictionary>> next;
     for (auto &lang : wanted)
     {
         if (lang != L"en" && lang != L"uk" && lang != L"ru")
             throw std::runtime_error("Unsupported dictionary language");
-        next.emplace(lang, Dictionary(folder / (lang + L".txt")));
+        next.emplace(lang, std::make_shared<const Dictionary>(folder / (lang + L".txt")));
     }
     dictionaries = std::move(next);
     languages = wanted;
 }
+void AutoCorrector::shareDictionaries(const AutoCorrector &source)
+{
+    dictionaries = source.dictionaries;
+    languages = source.languages;
+}
 void AutoCorrector::reject(std::wstring word, const Settings &settings)
 {
     while (!word.empty() && openingDelimiter(word.front(), settings))
@@ -132,7 +210,7 @@ size_t AutoCorrector::memoryBytes() const
 {
     size_t bytes = 0;
     for (auto &[language, d] : dictionaries)
-        bytes += d.bytes.capacity() + d.offsets.capacity() * sizeof(uint32_t);
+        bytes += d->bytes.capacity() + d->offsets.capacity() * sizeof(uint32_t);
     return bytes;
 }
 std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed, int source,
@@ -191,7 +269,7 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
     };
     // Valid words from either selected language are never changed.
     for (auto &[language, d] : dictionaries)
-        if (d.rank(word) || personal(language, word))
+        if (d->rank(word) || personal(language, word))
             return {};
     std::optional<AutoSuggestion> candidate;
     std::optional<std::wstring> matchedText;
@@ -211,7 +289,7 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
         auto converted = convert(word, layouts[source], layouts[i], true);
         if (converted == word || !safeAutoWord(converted, settings.autoMinLength))
             continue;
-        int rank = personal(dictionary->first, converted) ? 1 : dictionary->second.rank(converted);
+        int rank = personal(dictionary->first, converted) ? 1 : dictionary->second->rank(converted);
         if (!rank)
             continue;
         if (matchedText && *matchedText != converted)
@@ -233,7 +311,7 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
     auto consider = [&](const std::wstring &text)
     {
         if (text == small || text == found || text.size() < 4 || text.size() > 32) return true;
-        int rank = personalTargets.contains(text) ? 1 : dictionaries.at(sourceLanguage).rank(text);
+        int rank = personalTargets.contains(text) ? 1 : dictionaries.at(sourceLanguage)->rank(text);
         if (!rank) return true;
         if (!found.empty()) return false;
         found = text;

src/autocorrect.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "platform.h"
 #include <map>
+#include <memory>
 #include <set>
 #include <string_view>
 namespace ks
@@ -18,23 +19,30 @@ int matchAutoInput(const Run &, const std::wstring &, const std::vector<Layout>
 bool autoCorrectionAllowed(HWND, const Settings &);
 class AutoCorrector
 {
+    friend struct AutoCorrectorRegressionAccess;
     struct Dictionary
     {
+        // Front-coded UTF-8 words in independently searchable blocks of 32.
+        // Prefix/suffix lengths share a byte (15 escapes to a full byte length).
+        // Ranks use two bytes; 65535 escapes to a varint for larger custom ranks.
         std::string bytes;
         std::vector<uint32_t> offsets;
         std::string_view word(size_t) const;
         explicit Dictionary(const std::filesystem::path &);
         int rank(const std::wstring &) const;
     };
-    std::map<std::wstring, Dictionary> dictionaries;
+    std::map<std::wstring, std::shared_ptr<const Dictionary>> dictionaries;
     std::vector<std::wstring> languages;
     std::set<std::wstring> rejected;
 
   public:
     void configure(const std::filesystem::path &, const std::vector<std::wstring> &);
+    // Share immutable dictionary storage, keeping each consumer's undo rejections private.
+    void shareDictionaries(const AutoCorrector &);
     std::optional<AutoSuggestion> suggest(const std::wstring &, int source, const std::vector<Layout> &,
                                           const Settings &) const;
     void reject(std::wstring word, const Settings & = {});
+    // Referenced dictionary payload, including shared storage (do not sum across consumers).
     size_t memoryBytes() const;
 };
 } // namespace ks

src/history_preview.h

@@ -4,14 +4,28 @@
 #include <string>
 
 namespace ks {
+inline constexpr size_t HistoryThumbnailBudget = 1024 * 1024;
+inline constexpr size_t HistoryRichTextBudget = 256 * 1024;
 // Keep the visible working set even in unusually tall windows. Never evict a
 // visible preview to admit another visible preview: that creates a paint loop.
+template<class T, class Weight>
+void trimHistoryPreviews(std::map<std::wstring,T> &cache,
+                         const std::set<std::wstring> &visible, size_t limit,
+                         size_t byteLimit, Weight weight)
+{
+    size_t bytes = 0;
+    for (const auto &[id, value] : cache) bytes += weight(value);
+    for(auto it=cache.begin(); (cache.size()>limit || bytes>byteLimit) && it!=cache.end();)
+        if(!visible.contains(it->first)) {
+            bytes -= weight(it->second);
+            it=cache.erase(it);
+        }
+        else ++it;
+}
 template<class T>
 void trimHistoryPreviews(std::map<std::wstring,T> &cache,
                          const std::set<std::wstring> &visible, size_t limit=32)
 {
-    for(auto it=cache.begin(); cache.size()>limit && it!=cache.end();)
+    trimHistoryPreviews(cache, visible, limit, 0, [](const T &) { return size_t{}; });
-        if(!visible.contains(it->first)) it=cache.erase(it);
-        else ++it;
 }
 }

src/ocr.cpp

@@ -123,13 +123,16 @@ struct OcrStatics : IInspectable
 Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
 {
     Bytes encoded;
+    const Bytes *input = &encoded;
     for (const auto &f : clip.formats)
         if (f.name == L"PNG")
         {
-            encoded = f.data;
+            input = &f.data;
             break;
         }
-    if (encoded.empty())
+    if (input->empty())
+    {
+        input = &encoded;
         for (const auto &f : clip.formats)
             if ((f.id == CF_DIB || f.id == CF_DIBV5) && f.data.size() >= 40)
             {
@@ -146,19 +149,21 @@ Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
                 file.bfType = 0x4d42;
                 file.bfSize = (DWORD)(sizeof(file) + f.data.size());
                 file.bfOffBits = (DWORD)offset;
-                encoded.resize(sizeof(file));
+                encoded.resize(sizeof(file) + f.data.size());
                 memcpy(encoded.data(), &file, sizeof(file));
-                encoded.insert(encoded.end(), f.data.begin(), f.data.end());
+                memcpy(encoded.data() + sizeof(file), f.data.data(), f.data.size());
                 break;
             }
-    if (encoded.empty())
+    }
+    if (input->empty())
         throw std::runtime_error("This clipboard item has no supported image");
     Com<IWICImagingFactory> wic;
     check(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_IWICImagingFactory,
                            (void **)wic.out()));
     Com<IWICStream> stream;
     check(wic->CreateStream(stream.out()));
-    check(stream->InitializeFromMemory(encoded.data(), (DWORD)encoded.size()));
+    // WIC decoding only reads the stream. The clip outlives every WIC object here.
+    check(stream->InitializeFromMemory(const_cast<BYTE *>(input->data()), (DWORD)input->size()));
     Com<IWICBitmapDecoder> decoder;
     check(wic->CreateDecoderFromStream(stream.p, nullptr, WICDecodeMetadataCacheOnLoad, decoder.out()));
     Com<IWICBitmapFrameDecode> frame;

src/paste_probe.h

@@ -13,7 +13,7 @@ class PasteProbe
 
   public:
     std::wstring status = L"not-requested";
-    PasteProbe(bool enabled, const std::wstring &original)
+    PasteProbe(bool enabled, HWND target)
     {
         if (!enabled)
             return;
@@ -25,6 +25,18 @@ class PasteProbe
         automation->put_TransactionTimeout(200);
         if (FAILED(automation->GetFocusedElement(&element)) || !element)
             return;
+        if (target)
+        {
+            DWORD process{};
+            GetWindowThreadProcessId(target, &process);
+            int focusedProcess{};
+            if (!process || FAILED(element->get_CurrentProcessId(&focusedProcess)) ||
+                process != static_cast<DWORD>(focusedProcess) || GetForegroundWindow() != target)
+            {
+                status = L"focused-control-changed";
+                return;
+            }
+        }
         BOOL password = TRUE;
         if (FAILED(element->get_CurrentIsPassword(&password)) || password)
         {
@@ -35,6 +47,11 @@ class PasteProbe
                                                 (void **)&pattern)) ||
             !pattern)
             return;
+    }
+    PasteProbe(bool enabled, const std::wstring &original, HWND target = nullptr)
+        : PasteProbe(enabled, target)
+    {
+        if (!pattern) return;
         auto selected = read(1, false);
         auto normalize = [](std::wstring value)
         {

src/platform.cpp

@@ -159,6 +159,31 @@ void showRequestedWindow(HWND window)
     if (!IsWindowVisible(window))
         ShowWindow(window, SW_SHOW);
 }
+void showMenuAccessKeys(HMENU menu)
+{
+    // Mouse-opened popups ignore the owner's keyboard-cue state.
+    // Preserve the mnemonic and expose it in the right-hand hint column.
+    for (int i = 0; i < GetMenuItemCount(menu); ++i)
+    {
+        if (auto child = GetSubMenu(menu, i)) showMenuAccessKeys(child);
+        int length = GetMenuStringW(menu, i, nullptr, 0, MF_BYPOSITION);
+        std::wstring text(length + 1, L'\0');
+        GetMenuStringW(menu, i, text.data(), (int)text.size(), MF_BYPOSITION);
+        text.resize(length);
+        if (text.find(L'\t') != text.npos) continue;
+        for (size_t p = 0; p + 1 < text.size(); ++p)
+        {
+            if (text[p] != L'&') continue;
+            if (text[p + 1] == L'&') { ++p; continue; }
+            text += L"\t" + upper(text.substr(p + 1, 1));
+            MENUITEMINFOW item{sizeof(item)};
+            item.fMask = MIIM_STRING;
+            item.dwTypeData = text.data();
+            SetMenuItemInfoW(menu, i, TRUE, &item);
+            break;
+        }
+    }
+}
 bool activateWindow(HWND window)
 {
     if (!IsWindow(window))
@@ -579,10 +604,25 @@ std::recursive_mutex logGate;
 bool loggingEnabled = false;
 DiagnosticBuffer diagnosticBuffer;
 }
+size_t DiagnosticBuffer::expire(ULONGLONG now)
+{
+    size_t removed = 0;
+    while (!entries.empty() && now - entries.front().first > 30000)
+    {
+        entries.pop_front();
+        ++removed;
+    }
+    return removed;
+}
+void expireDiagnostics(ULONGLONG now)
+{
+    std::lock_guard lock(logGate);
+    diagnosticBuffer.expire(now);
+}
 std::wstring DiagnosticBuffer::record(const std::wstring &message, bool problem, ULONGLONG now)
 {
-    while (!entries.empty() && (entries.size() >= 128 || now - entries.front().first > 30000))
+    expire(now);
-        entries.pop_front();
+    while (entries.size() >= 128) entries.pop_front();
     entries.emplace_back(now, message);
     if (!problem)
         return {};

src/platform.h

@@ -38,6 +38,7 @@ HKL windowLayout(HWND);
 bool switchWindowLayout(HWND, HKL, const std::function<bool()> &valid);
 bool activateWindow(HWND);
 void showRequestedWindow(HWND);
+void showMenuAccessKeys(HMENU);
 bool ownsClipboard(HWND);
 bool webViewDescendant(DWORD owner, DWORD host,
                        const std::function<std::optional<std::pair<DWORD, std::wstring>>(DWORD)> &read);
@@ -71,10 +72,12 @@ class DiagnosticBuffer
 {
     std::deque<std::pair<ULONGLONG, std::wstring>> entries;
   public:
+    size_t expire(ULONGLONG now);
     std::wstring record(const std::wstring &message, bool problem, ULONGLONG now);
     void clear() { entries.clear(); }
 };
 void setLoggingEnabled(bool enabled);
+void expireDiagnostics(ULONGLONG now);
 void diagnosticEvent(const std::wstring &message, bool problem = false);
 void diagnosticOperation(const std::string &json);
 std::wstring readDiagnosticLog(bool previous);

src/screenshot.cpp

@@ -783,12 +783,13 @@ HCURSOR actionCursor(const Capture &c,std::pair<int,MarkPart> hit,bool inside)
     if(hit.second==MarkPart::Body || hit.second==MarkPart::Label) cursor=IDC_SIZEALL;
     else if(hit.second==MarkPart::Rotation) cursor=IDC_HAND;
     else if(hit.second>=MarkPart::Vertex0 && hit.second<=MarkPart::Vertex2) cursor=IDC_SIZEALL;
-    else if(hit.second==MarkPart::Radius) cursor=IDC_SIZEWE;
+    else if(hit.second==MarkPart::Start || hit.second==MarkPart::End || hit.second==MarkPart::Radius)
-    else if(hit.second==MarkPart::Start || hit.second==MarkPart::End || hit.second==MarkPart::Thickness) {
+        cursor=IDC_SIZEALL;
+    else if(hit.second==MarkPart::Thickness) {
         const auto &mark=c.marks[hit.first];
-        auto [from,to]=hit.second==MarkPart::Thickness?thicknessSegment(mark):std::pair{mark.from,mark.to};
+        auto [from,to]=thicknessSegment(mark);
         double angle=std::atan2(double(to.y-from.y),double(to.x-from.x));
-        if(hit.second==MarkPart::Thickness) angle+=3.141592653589793/2;
+        angle+=3.141592653589793/2;
         int axis=(int(std::lround(angle/(3.141592653589793/4)))+8)%4;
         const LPCWSTR cursors[]{IDC_SIZEWE,IDC_SIZENWSE,IDC_SIZENS,IDC_SIZENESW};
         cursor=cursors[axis];

src/screenshot_activation.cpp

@@ -50,6 +50,30 @@ void registerScreenshotNotifications()
     // Notify the shell that notification identity/activation registration changed.
     SHChangeNotify(SHCNE_ASSOCCHANGED,SHCNF_IDLIST,nullptr,nullptr);
 }
+HANDLE startScreenshotNotificationRegistration()
+{
+    auto path=std::filesystem::path(executable()).parent_path()/L"KSwitcher.Screenshot.exe";
+    auto command=L"\""+path.wstring()+L"\" --register-notifications";
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags=STARTF_USESHOWWINDOW; startup.wShowWindow=SW_HIDE;
+    PROCESS_INFORMATION process{};
+    if(!CreateProcessW(path.c_str(),command.data(),nullptr,nullptr,FALSE,CREATE_NO_WINDOW,
+                       nullptr,path.parent_path().c_str(),&startup,&process))
+        throw std::runtime_error(utf8(lastError(L"Cannot start notification registration helper")));
+    CloseHandle(process.hThread);
+    return process.hProcess;
+}
+void registerScreenshotNotificationsInHelper()
+{
+    auto process=startScreenshotNotificationRegistration();
+    auto wait=WaitForSingleObject(process,10000);
+    DWORD code=ERROR_GEN_FAILURE;
+    bool completed=wait==WAIT_OBJECT_0 && GetExitCodeProcess(process,&code);
+    CloseHandle(process);
+    if(!completed || code)
+        throw std::runtime_error(completed ? "Notification registration helper failed: "+std::to_string(code)
+                                          : "Notification registration helper did not complete within 10 seconds");
+}
 bool validScreenshotToken(const std::wstring &id)
 {
     if(id.size()!=36) return false;

src/screenshot_notifications.cpp

@@ -206,7 +206,7 @@ bool notifyUpdateAvailable(const std::wstring &version)
 {
     try {
         // Reuse the screenshot notification identity, Windows settings and COM activator.
-        registerScreenshotNotifications();
+        registerScreenshotNotificationsInHelper();
         ComPtr<Notifications::IToastNotificationManagerStatics> manager;
         String managerClass(L"Windows.UI.Notifications.ToastNotificationManager");
         check(RoGetActivationFactory(managerClass.value,IID_PPV_ARGS(&manager)));

src/screenshot_notifications.h

@@ -4,6 +4,10 @@ namespace ks {
 bool notifyScreenshot(const Clip &);
 std::string screenshotNotificationError();
 void registerScreenshotNotifications();
+// Caller owns the returned process handle; the helper exits after registration.
+HANDLE startScreenshotNotificationRegistration();
+// For background notification workers only; bounded wait, never on the UI thread.
+void registerScreenshotNotificationsInHelper();
 int runScreenshotToastActivator();
 DWORD startScreenshotActivationListener();
 bool validScreenshotToken(const std::wstring &);

src/ui.cpp

@@ -479,12 +479,14 @@ struct HistoryView
 {
     App *app{};
     std::vector<Entry> items;
+    std::wstring rememberedSelection, rememberedTop;
     uint64_t generation{};
     std::map<std::wstring, Pixels> thumbnails;
     std::map<std::wstring, std::string> richTexts;
     HWND rich{};
     std::set<std::wstring> pending;
     bool scrolling{};
+    bool closed{};
 };
 bool selectedImage(HWND w, HistoryView *v)
 {
@@ -502,6 +504,7 @@ std::wstring selected(HWND w, HistoryView *v)
 }
 void search(HWND w, HistoryView *v)
 {
+    v->closed = false;
     auto q = value(w, 101);
     auto generation = ++v->generation;
     v->pending.clear();
@@ -770,6 +773,7 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
         }
         case WM_TIMER:
             KillTimer(w, 1);
+            if (v->closed) return 0;
             search(w, v);
             return 0;
         case ResultsMessage:
@@ -778,8 +782,10 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             if (result->generation != v->generation)
                 return 0;
             auto old = selected(w, v);
+            if (old.empty()) old = v->rememberedSelection;
             int top=(int)SendDlgItemMessageW(w,102,LB_GETTOPINDEX,0,0);
             auto topId=top>=0 && top<(int)v->items.size()?v->items[top].id:L"";
+            if (topId.empty()) topId = v->rememberedTop;
             v->items = std::move(result->items);
             SendDlgItemMessageW(w, 102, WM_SETREDRAW, FALSE, 0);
             SendDlgItemMessageW(w, 102, LB_RESETCONTENT, 0, 0);
@@ -823,8 +829,10 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 v->richTexts[result->id] = std::move(result->rtf);
             else
                 v->thumbnails[result->id] = std::move(result->pixels);
-            trimHistoryPreviews(v->thumbnails,visible);
+            trimHistoryPreviews(v->thumbnails,visible,32,HistoryThumbnailBudget,
-            trimHistoryPreviews(v->richTexts,visible);
+                                [](const Pixels &p) { return p.bgra.capacity(); });
+            trimHistoryPreviews(v->richTexts,visible,32,HistoryRichTextBudget,
+                                [](const std::string &s) { return s.capacity(); });
             if(repaint) InvalidateRect(list,&changed,FALSE);
             return 0;
         }
@@ -867,6 +875,7 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             AppendMenuW(menu, MF_STRING, 113, L"&Delete");
             AppendMenuW(menu, MF_STRING, 114, selectedImage(w,v)?L"&Edit image in screenshot editor":L"&Open full item");
             AppendMenuW(menu, MF_STRING, 115, L"&Copy text from image (OCR)");
+            showMenuAccessKeys(menu);
             int cmd = TrackPopupMenu(menu, TPM_RETURNCMD, p.x, p.y, 0, w, nullptr);
             DestroyMenu(menu);
             if (cmd)
@@ -874,14 +883,23 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             return 0;
         }
         case WM_CLOSE:
+        {
+            v->rememberedSelection = selected(w, v);
+            int top = (int)SendDlgItemMessageW(w,102,LB_GETTOPINDEX,0,0);
+            v->rememberedTop = top >= 0 && top < (int)v->items.size() ? v->items[top].id : L"";
+            KillTimer(w, 1);
+            v->closed = true;
+            ++v->generation; // Discard search/preview results queued before closing.
             ShowWindow(w, SW_HIDE);
+            SendDlgItemMessageW(w,102,LB_RESETCONTENT,0,0);
+            std::vector<Entry>().swap(v->items);
             v->thumbnails.clear();
             v->richTexts.clear();
             if (v->rich)
                 SetWindowTextW(v->rich, L"");
             v->pending.clear();
-            ++v->generation;
             return 0;
+        }
         case WM_NCDESTROY:
             disposeFont(w);
             v->app->historyWindow = nullptr;
@@ -1338,6 +1356,46 @@ void showOcrOptions(HWND parent, SettingsView *v)
     showRequestedWindow(w); SetForegroundWindow(w);
 }
 #include "ui_sync.inl"
+bool settingsChanged(HWND w, SettingsView *v)
+{
+    try
+    {
+        return encodeSettings(collectSettings(w, v)) != encodeSettings(v->app->settings);
+    }
+    catch (const std::exception &)
+    {
+        // Invalid edits are unsaved changes too. Allow discarding them without
+        // requiring the user to repair the fields first.
+        return true;
+    }
+}
+void closeSettings(HWND w, SettingsView *v)
+{
+    if (settingsChanged(w, v))
+    {
+        int choice = MessageBoxW(w,
+            L"You have unsaved settings changes. Save them before closing?\n\n"
+            L"Yes: save and close.\nNo: discard changes.\nCancel: keep editing.",
+            L"KSwitcher — Unsaved settings", MB_YESNOCANCEL | MB_ICONWARNING | MB_DEFBUTTON3);
+        if (choice != IDYES && choice != IDNO)
+            return;
+        if (choice == IDYES)
+        {
+            try
+            {
+                if (v->app->busy)
+                    throw std::runtime_error("Wait for the current text operation to finish");
+                v->app->applySettings(collectSettings(w, v));
+            }
+            catch (const std::exception &e)
+            {
+                error(w, e);
+                return;
+            }
+        }
+    }
+    DestroyWindow(w);
+}
 LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 {
     if (msg == WM_DPICHANGED)
@@ -1403,7 +1461,7 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             }
             if (id == IDCANCEL)
             {
-                DestroyWindow(w);
+                closeSettings(w, v);
                 return 0;
             }
             if (id == 250)
@@ -1454,7 +1512,7 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             break;
         }
         case WM_CLOSE:
-            DestroyWindow(w);
+            closeSettings(w, v);
             return 0;
         case WM_NCDESTROY:
             disposeFont(w);

src/update.h

@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-inline constexpr wchar_t AppVersion[] = L"0.6.29";
+inline constexpr wchar_t AppVersion[] = L"0.6.36";
 inline constexpr UINT UpdateMessage = WM_APP + 7;
 inline constexpr UINT UpdateCheckIntervalMs = 6 * 60 * 60 * 1000;
 inline constexpr UINT UpdateNotificationRetryMs = 5 * 60 * 1000;

tests/dictionary.cpp

@@ -0,0 +1,85 @@
+#include "autocorrect.h"
+#include <algorithm>
+#include <chrono>
+#include <fstream>
+#include <iostream>
+#include <psapi.h>
+#include <random>
+namespace ks {
+struct AutoCorrectorRegressionAccess {
+ static int rank(const AutoCorrector &c,const std::wstring &lang,const std::wstring &word) {
+  return c.dictionaries.at(lang)->rank(word);
+ }
+ static std::vector<int> ranks(const std::filesystem::path &path,const std::vector<std::wstring> &words) {
+  AutoCorrector::Dictionary d(path);
+  std::vector<int> values;for(const auto &word:words)values.push_back(d.rank(word));return values;
+ }
+};
+}
+int main(int argc,char **argv) {
+ try {
+  auto start=std::chrono::steady_clock::now();
+  ks::AutoCorrector c;c.configure(L"dictionaries",{L"en",L"uk",L"ru"});
+  PROCESS_MEMORY_COUNTERS_EX m{};
+  GetProcessMemoryInfo(GetCurrentProcess(),reinterpret_cast<PROCESS_MEMORY_COUNTERS*>(&m),sizeof(m));
+  std::cout<<"dictionary_bytes="<<c.memoryBytes()<<" private_bytes="<<m.PrivateUsage
+   <<" load_ms="<<std::chrono::duration<double,std::milli>(std::chrono::steady_clock::now()-start).count()<<'\n';
+  struct Query {std::wstring language,word; int rank;};
+  std::vector<Query> queries;
+  for(const auto *lang:{L"en",L"uk",L"ru"}) {
+   std::ifstream input(std::filesystem::path(L"dictionaries")/(std::wstring(lang)+L".txt"));
+   std::map<std::wstring,int> expected;
+   for(std::string line;std::getline(input,line);) {
+    auto tab=line.find('\t');auto word=ks::wide(line.substr(0,tab));auto rank=std::stoi(line.substr(tab+1));
+    auto [it,added]=expected.emplace(word,rank);if(!added)it->second=std::min(it->second,rank);
+   }
+   if(expected.empty())throw std::runtime_error("Missing benchmark dictionary");
+   for(auto &[word,rank]:expected) {
+    if(ks::AutoCorrectorRegressionAccess::rank(c,lang,word)!=rank)throw std::runtime_error("Dictionary rank differs from source");
+    if(ks::AutoCorrectorRegressionAccess::rank(c,lang,word+L"~")!=0)throw std::runtime_error("False dictionary hit");
+    queries.push_back({lang,word,rank});queries.push_back({lang,word+L"~",0});
+   }
+  }
+  std::mt19937 random(42);std::shuffle(queries.begin(),queries.end(),random);
+  uint64_t checksum=0,expected=0;
+  for(auto &q:queries)expected+=q.rank;
+  start=std::chrono::steady_clock::now();
+  for(int pass=0;pass<5;++pass)for(auto &q:queries)checksum+=ks::AutoCorrectorRegressionAccess::rank(c,q.language,q.word);
+  auto ms=std::chrono::duration<double,std::milli>(std::chrono::steady_clock::now()-start).count();
+  if(checksum!=expected*5)throw std::runtime_error("Lookup checksum mismatch");
+  std::cout<<"verified_words="<<queries.size()/2<<" queries="<<queries.size()*5<<" lookup_ms="<<ms
+   <<" ns_per_lookup="<<ms*1000000/(queries.size()*5)<<" checksum="<<checksum<<'\n';
+  auto fixture=std::filesystem::temp_directory_path()/(L"KSwitcher-dictionary-"+
+      std::to_wstring(GetCurrentProcessId())+L"-"+std::to_wstring(GetTickCount64())+L".txt");
+  struct RemoveFixture { std::filesystem::path path; ~RemoveFixture(){std::error_code ec;std::filesystem::remove(path,ec);} } cleanup{fixture};
+  auto put=[&](const std::string &text){ks::atomicWrite(fixture,ks::Bytes(text.begin(),text.end()));};
+  std::string text="duplicate\t9\r\nduplicate\t2\n";
+  std::vector<std::wstring> words;
+  std::vector<int> expectedRanks;
+  for(int i=129;i>=0;--i) {
+   auto word=L"prefix_"+std::to_wstring(i);
+   text+=ks::utf8(word)+"\t"+std::to_string(i+1)+"\n";
+   words.push_back(word);expectedRanks.push_back(i+1);
+  }
+  text+=std::string(160,'x')+"\t2147483647"; // Maximum length/rank, no final newline.
+  words.insert(words.end(),{std::wstring(160,L'x'),L"DUPLICATE",L"",L"prefix_",L"zzzz"});
+  expectedRanks.insert(expectedRanks.end(),{2147483647,2,0,0,0});
+  for(auto rank:{65534,65535,65536}) {
+   auto word=std::wstring(159,L'x')+wchar_t(L'y'+rank-65534);
+   text+="\n"+ks::utf8(word)+"\t"+std::to_string(rank);
+   words.push_back(word);expectedRanks.push_back(rank);
+  }
+  put(text);
+  if(ks::AutoCorrectorRegressionAccess::ranks(fixture,words)!=expectedRanks)
+   throw std::runtime_error("Block boundaries, duplicate ranks or maximum values failed");
+  for(const auto &invalid:std::vector<std::string>{"","missing-tab","x\t0","x\t-1","x\t2147483648",std::string(161,'x')+"\t1","\t1","x\t1bad"}) {
+   put(invalid);bool rejected=false;
+   try {ks::AutoCorrectorRegressionAccess::ranks(fixture,{L"x"});}catch(const std::runtime_error &){rejected=true;}
+   if(!rejected)throw std::runtime_error("Invalid dictionary was accepted");
+  }
+  const bool baseline=argc==2 && std::string(argv[1])=="--baseline";
+  if(!baseline && c.memoryBytes()>=1536*1024)throw std::runtime_error("Bundled dictionaries exceed compact memory budget");
+  std::cout<<"Passed complete dictionary equivalence and format regressions\n";
+  return 0;
+ }catch(const std::exception&e){std::cerr<<e.what()<<'\n';return 1;}
+}

tests/input.cpp

@@ -5,6 +5,19 @@
 #include <commctrl.h>
 #include <iostream>
 #include <cmath>
+static int settingsCloseChoice = IDCANCEL;
+static int settingsClosePrompts = 0;
+static void CALLBACK answerSettingsClose(HWND, UINT, UINT_PTR, DWORD)
+{
+    HWND dialog = FindWindowW(L"#32770", L"KSwitcher — Unsaved settings");
+    DWORD process{};
+    if (dialog && GetWindowThreadProcessId(dialog, &process) == GetCurrentThreadId() &&
+        process == GetCurrentProcessId())
+    {
+        ++settingsClosePrompts;
+        SendMessageW(dialog, WM_COMMAND, settingsCloseChoice, 0);
+    }
+}
 LRESULT CALLBACK countControlMoves(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR data)
 {
     if (message == WM_WINDOWPOSCHANGING) ++*reinterpret_cast<int *>(data);
@@ -12,6 +25,38 @@ LRESULT CALLBACK countControlMoves(HWND w, UINT message, WPARAM wp, LPARAM lp, U
 }
 namespace ks {
 struct InputRegressionAccess {
+    static bool idleUndo(App &a) {
+        a.last=LastTransform{}; a.last->at=100;
+        a.releaseIdleMemory(120100);
+        if (!a.last) return false;
+        a.busy=true;
+        a.releaseIdleMemory(120101);
+        if (!a.last) { a.busy=false; return false; }
+        a.busy=false;
+        a.releaseIdleMemory(120101);
+        return !a.last;
+    }
+    static bool releasedSync(const App &a) {
+        return a.syncSnapshot.capacity()==0 && a.syncResult.settings.capacity()==0 &&
+            a.syncResult.base.capacity()==0 && a.syncResult.conflicts.capacity()==0;
+    }
+    static bool completedSync(App &a, int mode) {
+        sampleConflicts(a);
+        auto conflicts=encodeSyncConflicts(a.pendingSyncConflicts);
+        a.syncConnection=loadSyncConfig(a.data);
+        a.syncSnapshot=encodeSettings(a.settings);
+        a.syncResult={mode!=1,sharedSyncSettings(a.settings),2,L"test"};
+        a.syncResult.base=a.syncResult.settings;
+        a.syncResult.conflicts=a.pendingSyncConflicts;
+        if(mode==2) a.syncResult.settings={1,2,3}; // Decode exception after joining.
+        a.syncWorker=std::thread([]{});
+        a.syncRunning=true; a.syncDone=true; a.busy=true;
+        a.pollSync();
+        bool retained=!a.syncSnapshot.empty() && a.syncRunning;
+        a.busy=false; a.pollSync();
+        return retained && releasedSync(a) && !a.syncRunning &&
+            encodeSyncConflicts(a.pendingSyncConflicts)==conflicts;
+    }
     static inline bool delivery = true;
     static inline int notifications = 0;
     static bool notify(const std::wstring &) { ++notifications; return delivery; }
@@ -31,6 +76,7 @@ struct InputRegressionAccess {
         a.syncRunning=true; a.syncDone=true;
         a.pollSync();
         return encodeSettings(a.settings)==before && !a.syncRunning &&
+            releasedSync(a) &&
             !std::filesystem::exists(a.data/L"sync-base.bin");
     }
     static bool syncBackoff(App &a) {
@@ -80,6 +126,25 @@ int main(int argc, char **argv) {
     try {
         INITCOMMONCONTROLSEX controls{sizeof(controls),ICC_STANDARD_CLASSES|ICC_LISTVIEW_CLASSES};
         InitCommonControlsEx(&controls);
+        {
+            HMENU menu = CreatePopupMenu(), child = CreatePopupMenu();
+            AppendMenuW(menu,MF_STRING | MF_CHECKED,1,L"&Settings…");
+            AppendMenuW(menu,MF_STRING,2,L"Copy\tCtrl+C");
+            AppendMenuW(child,MF_STRING,3,L"Rock && &Roll");
+            AppendMenuW(menu,MF_POPUP,(UINT_PTR)child,L"&Pause");
+            ks::showMenuAccessKeys(menu);
+            ks::showMenuAccessKeys(menu);
+            wchar_t label[128]{};
+            GetMenuStringW(menu,1,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"&Settings…\tS" &&
+                    (GetMenuState(menu,1,MF_BYCOMMAND)&MF_CHECKED),
+                    "visible menu mnemonic is idempotent and preserves item state");
+            GetMenuStringW(menu,2,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"Copy\tCtrl+C","existing menu shortcut hints are retained");
+            GetMenuStringW(child,3,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"Rock && &Roll\tR","submenu hints skip escaped ampersands");
+            DestroyMenu(menu);
+        }
         {
             ks::App app(GetModuleHandleW(nullptr),true,temp);
             ks::InputRegressionAccess::setup(app);
@@ -629,6 +694,49 @@ int main(int argc, char **argv) {
             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 timer = SetTimer(nullptr, 0, 10, answerSettingsClose);
+                require(timer != 0, "settings close prompt responder");
+                SendMessageW(app.settingsWindow, WM_CLOSE, 0, 0);
+                require(!app.settingsWindow && settingsClosePrompts == 0,
+                        "unchanged settings close without prompting");
+                ks::showSettings(app,false);
+                auto settingsWindow = app.settingsWindow;
+                auto initial = SendDlgItemMessageW(settingsWindow,205,BM_GETCHECK,0,0);
+                SendDlgItemMessageW(settingsWindow,205,BM_SETCHECK,!initial,0);
+                SendMessageW(settingsWindow, WM_CLOSE, 0, 0);
+                require(IsWindow(settingsWindow) && settingsClosePrompts == 1,
+                        "cancel close preserves changed settings");
+                SendDlgItemMessageW(settingsWindow,205,BM_SETCHECK,initial,0);
+                SendMessageW(settingsWindow, WM_CLOSE, 0, 0);
+                require(!app.settingsWindow && settingsClosePrompts == 1,
+                        "reverted settings close without prompting");
+                ks::showSettings(app,false);
+                SetDlgItemTextW(app.settingsWindow,240,L"invalid");
+                settingsCloseChoice = IDNO;
+                SendMessageW(app.settingsWindow,WM_COMMAND,IDCANCEL,0);
+                require(!app.settingsWindow && settingsClosePrompts == 2,
+                        "Cancel button allows discarding invalid edits");
+                auto originalSettings = app.settings;
+                // The isolated harness has no keyboard hook; save without shortcuts.
+                app.settings.toggle = app.settings.casing = app.settings.translit =
+                    app.settings.undo = app.settings.clipboard = app.settings.screenshot = L"";
+                app.settings.direct.assign(app.layouts.size(), L"");
+                ks::showSettings(app,false);
+                SendDlgItemMessageW(app.settingsWindow,208,BM_SETCHECK,
+                                    originalSettings.writeLog ? BST_UNCHECKED : BST_CHECKED,0);
+                settingsCloseChoice = IDYES;
+                SendMessageW(app.settingsWindow,WM_CLOSE,0,0);
+                require(!app.settingsWindow && settingsClosePrompts == 3 &&
+                        app.settings.writeLog != originalSettings.writeLog &&
+                        ks::loadSettings(app.data / L"settings.json",app.layouts).writeLog == app.settings.writeLog,
+                        "Yes saves settings to disk and applies them before closing");
+                app.settings = originalSettings;
+                ks::setLoggingEnabled(originalSettings.writeLog);
+                KillTimer(nullptr,timer);
+                settingsCloseChoice = IDCANCEL;
+                ks::showSettings(app,false);
+            }
             require(GetDlgItem(app.settingsWindow,258)!=nullptr,"sync available without local opt-in");
             // Mnemonics only target visible controls; show without taking foreground focus.
             ShowWindow(app.settingsWindow,SW_SHOWNOACTIVATE);
@@ -716,6 +824,10 @@ int main(int argc, char **argv) {
             require(IsWindowEnabled(app.settingsWindow),"closing sync restores parent");
             require(ks::InputRegressionAccess::staleSync(app,false),"in-flight sync cannot overwrite newer local edits");
             require(ks::InputRegressionAccess::staleSync(app,true),"disconnect discards in-flight downloaded profile");
+            require(ks::InputRegressionAccess::idleUndo(app),"idle cleanup retains available/busy Undo and frees expired Undo");
+            for(int mode=0;mode<3;++mode)
+                require(ks::InputRegressionAccess::completedSync(app,mode),
+                        "completed, failed and invalid sync release buffers but preserve conflict choices");
             require(ks::InputRegressionAccess::syncBackoff(app),"saving settings preserves authentication error backoff");
             SendMessageW(app.settingsWindow,WM_COMMAND,255,0);
             auto autoOptions=FindWindowW(L"KSwitcher.AutoOptions",nullptr);
@@ -774,6 +886,14 @@ int main(int argc, char **argv) {
             SendDlgItemMessageW(autoOptions,415,BM_SETCHECK,BST_CHECKED,0);
             SendMessageW(autoOptions,WM_COMMAND,IDOK,0);
             require(!IsWindow(autoOptions),"personal words accepted without file editing");
+            {
+                auto timer = SetTimer(nullptr,0,10,answerSettingsClose);
+                auto before = settingsClosePrompts;
+                SendMessageW(app.settingsWindow,WM_CLOSE,0,0);
+                KillTimer(nullptr,timer);
+                require(app.settingsWindow && settingsClosePrompts == before + 1,
+                        "accepted personal dictionary edits trigger unsaved settings warning");
+            }
             SendMessageW(app.settingsWindow,WM_COMMAND,255,0);
             autoOptions=FindWindowW(L"KSwitcher.AutoOptions",nullptr);
             ShowWindow(autoOptions,SW_HIDE);
@@ -819,6 +939,25 @@ int main(int argc, char **argv) {
                 SetDlgItemTextW(history,101,L"");
                 require(pumpUntil(2),"clearing search restores history");
                 require(GetFocus()==originalFocus,"history search preserves focus");
+                SendDlgItemMessageW(history,102,LB_SETCURSEL,1,0);
+                ks::refreshHistory(app); // A result may still be in flight when closing.
+                SendMessageW(history,WM_CLOSE,0,0);
+                SendMessageW(history,WM_TIMER,1,0); // KillTimer cannot retract a posted timer message.
+                require(pumpUntil(0),"closing history releases list strings");
+                auto until=GetTickCount64()+250;
+                while(GetTickCount64()<until) {
+                    MSG message{};
+                    while(PeekMessageW(&message,nullptr,0,0,PM_REMOVE)) {
+                        TranslateMessage(&message); DispatchMessageW(&message);
+                    }
+                    Sleep(5);
+                }
+                require(SendDlgItemMessageW(history,102,LB_GETCOUNT,0,0)==0,
+                        "late search results do not refill closed history");
+                ks::refreshHistory(app);
+                require(pumpUntil(2),"history reloads after releasing hidden rows");
+                require(SendDlgItemMessageW(history,102,LB_GETCURSEL,0,0)==1,
+                        "history retains selected record across close and reload");
             }
             auto childRect=[&](int id) { RECT r{}; GetWindowRect(GetDlgItem(history,id),&r); MapWindowPoints(nullptr,history,(POINT*)&r,2); return r; };
             RECT historyFrame{}; GetWindowRect(history,&historyFrame);

tests/integration.cpp

@@ -9,6 +9,7 @@ namespace ks
 {
 struct InputRegressionAccess
 {
+    static bool hasLast(App &app) { return app.last.has_value(); }
     static bool deferring(App &app)
     {
         std::lock_guard lock(app.stateMutex);
@@ -28,6 +29,8 @@ int pasteBehavior = 0;
 int enterPresses = 0;
 int copyFailuresRemaining = 0, copyRequests = 0;
 int droppedSelectionKeys = 0;
+bool trimCopiedSpaces = false;
+int trimmedCopies = 0;
 bool temporaryClipboardExcluded = true;
 bool clipboardAccessTimedOut = false;
 LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
@@ -76,10 +79,42 @@ LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_P
                 --copyFailuresRemaining;
                 return 0;
             }
+            if (trimCopiedSpaces)
+            {
+                auto result = DefSubclassProc(w, message, wp, lp);
+                // Native EDIT closes the clipboard in its copy handler, including
+                // our outer opening. Reopen it before changing its published data.
+                if (!OpenClipboard(w))
+                {
+                    clipboardAccessTimedOut = true;
+                    return result;
+                }
+                auto handle = GetClipboardData(CF_UNICODETEXT);
+                auto data = handle ? static_cast<const wchar_t *>(GlobalLock(handle)) : nullptr;
+                if (data)
+                {
+                    std::wstring copied(data);
+                    GlobalUnlock(handle);
+                    const auto originalSize = copied.size();
+                    while (!copied.empty() && copied.back() == L' ') copied.pop_back();
+                    auto replacement = GlobalAlloc(GMEM_MOVEABLE, (copied.size() + 1) * sizeof(wchar_t));
+                    auto output = GlobalLock(replacement);
+                    memcpy(output, copied.c_str(), (copied.size() + 1) * sizeof(wchar_t));
+                    GlobalUnlock(replacement);
+                    if (!EmptyClipboard() || !SetClipboardData(CF_UNICODETEXT, replacement))
+                    {
+                        GlobalFree(replacement);
+                        clipboardAccessTimedOut = true;
+                    }
+                    else if (copied.size() != originalSize) ++trimmedCopies;
+                }
+                return result;
+            }
         }
     }
     if (message == WM_PASTE && pasteBehavior)
     {
+        if (pasteBehavior == 3) { pasteBehavior = 0; return 0; }
         if (pasteBehavior == 2) SendMessageW(w, EM_REPLACESEL, TRUE, (LPARAM)L"other!");
         return 0;
     }
@@ -371,6 +406,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 require(text() == L"ghbdtn" && rows.back().outcome == L"Original text remained",
                         "blocked paste records original text remaining in the actual editor");
                 require(ks::readClipboard(app->window).text() == sentinel, "readback preserves clipboard after blocked paste");
+                require(!ks::InputRegressionAccess::hasLast(*app), "failed paste does not retain a fictional previous result");
                 pasteBehavior = 2;
                 prepare(L"ghbdtn", true);
                 app->transform(ks::Direct + ru);
@@ -381,6 +417,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
                 require(text() == L"other!" && rows.back().outcome == L"Readback differs",
                         "unexpected editor content records readback mismatch");
+                require(!ks::InputRegressionAccess::hasLast(*app), "changed readback cannot seed repeat conversion");
                 pasteBehavior = 0;
                 prepare(L"привет", true);
                 app->transform(ks::Direct + ru);
@@ -449,9 +486,95 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                         details.find(L"Selection initial match=0") != details.npos &&
                         details.find(L"SelectPrevious") != details.npos,
                         "incident includes clipboard and selection stages");
-                finish();
+                pasteBehavior = 3;
+                prepare(L"=nhtdjuf", true);
+                app->transform(ks::Direct + ru);
+                stage = 49;
                 break;
             }
+            case 49:
+            {
+                require(text() == L"=тревога" && pasteBehavior == 0,
+                        "native Edit retries one ignored paste only while original remains selected");
+                require(ks::readClipboard(app->window).text() == sentinel, "native paste retry restores clipboard");
+                trimCopiedSpaces = true;
+                app->settings.writeLog = false;
+                prepare(L"OLDghbdtn  NEXT", false);
+                SendMessageW(field, EM_SETSEL, 11, 11);
+                record(L"ghbdtn  ");
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 50:
+                require(text() == L"OLDпривет  NEXT", "trimmed clipboard recovery preserves two spaces and surrounding text without logging");
+                app->transform(ks::Direct + en);
+                break;
+            case 51:
+                require(text() == L"OLDghbdtn  NEXT", "repeat conversion preserves accessibility-proven spaces");
+                app->transform(ks::Undo);
+                break;
+            case 52:
+                require(text() == L"OLDпривет  NEXT", "undo preserves accessibility-proven spaces");
+                prepare(L"ghbdtn", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            case 53:
+                require(text() == L"ghbdtn", "missing real space cannot be inferred from tracked keys");
+                prepare(L"wrong ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            case 54:
+                require(text() == L"wrong ", "unrelated selection remains rejected with trimmed clipboard");
+                app->settings.autoCorrect = true;
+                app->settings.autoLanguages = {L"en", L"ru"};
+                // The worker now shares the predictor's immutable dictionaries.
+                // This fixture changes settings directly instead of applySettings.
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
+                app->autoCorrector = ks::AutoCorrector{};
+                ActivateKeyboardLayout(app->layouts[en].handle, 0);
+                prepare(L"ghbdtn ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::AutoCorrect);
+                break;
+            case 55:
+                require(text() == L"привет ", "automatic correction recovers copied trailing space without logging");
+                app->transform(ks::Undo);
+                break;
+            case 56:
+            {
+                require(text() == L"ghbdtn ", "automatic correction undo retains recovered space");
+                require(ks::readClipboard(app->window).text() == sentinel, "space recovery restores clipboard");
+                pasteBehavior = 1;
+                prepare(L"ghbdtn ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 57:
+            {
+                require(text() == L"ghbdtn " && !ks::InputRegressionAccess::hasLast(*app),
+                        "recovered selection with blocked paste clears repeat state even without logging");
+                require(trimmedCopies >= 7, "fixture actually stripped spaces during recovery scenarios");
+                pasteBehavior = 0;
+                trimCopiedSpaces = false;
+                // User-selected middle range, followed by the same command with
+                // no selection: retain both surrounding text and trailing spaces.
+                prepare(L"OLDghbdtn  NEXT", false);
+                SendMessageW(field, EM_SETSEL, 3, 11);
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 58:
+                require(text() == L"OLDпривет  NEXT", "explicit middle selection preserves surrounding text");
+                app->transform(ks::Direct + en);
+                break;
+            case 59:
+                require(text() == L"OLDghbdtn  NEXT", "hotkey without selection reconverts only the previous middle range");
+                require(ks::readClipboard(app->window).text() == sentinel, "selected and repeated conversions restore clipboard");
+                finish();
+                break;
             case 30:
             case 32:
             case 34:
@@ -853,7 +976,7 @@ int main(int argc, char **argv)
             field =
                 CreateWindowW(L"EDIT", L"", WS_CHILD | WS_VISIBLE | WS_BORDER | ES_MULTILINE | ES_WANTRETURN,
                               20, 20, 590, 230, host, nullptr, cls.hInstance, nullptr);
-            deadline = GetTickCount64() + 30000;
+            deadline = GetTickCount64() + 60000;
             SetWindowSubclass(field, observeEnter, 1, 0);
             if (typosOnly || (argc > 1 && std::string(argv[1]) == "--typing-only"))
                 stage = 20;

tests/screenshot_registration.cpp

@@ -5,9 +5,11 @@
 static std::wstring programs;
 static std::wstring activationExecutable, activationCommand;
 static int activationCalls{};
+static DWORD launchFlags{}; static bool inheritsHandles{};
 static BOOL WINAPI testCreateProcess(LPCWSTR path, LPWSTR command, LPSECURITY_ATTRIBUTES,
-    LPSECURITY_ATTRIBUTES, BOOL, DWORD, LPVOID, LPCWSTR, LPSTARTUPINFOW, LPPROCESS_INFORMATION)
+    LPSECURITY_ATTRIBUTES, BOOL inherit, DWORD flags, LPVOID, LPCWSTR, LPSTARTUPINFOW, LPPROCESS_INFORMATION)
 {
+    launchFlags=flags; inheritsHandles=inherit;
     ++activationCalls; activationExecutable=path; activationCommand=command;
     SetLastError(ERROR_CANCELLED); return FALSE; // Inspect activation without starting any program.
 }
@@ -55,6 +57,14 @@ int main()
         valid=id.vt==VT_CLSID && *id.puuid==ks::ActivatorId; PropVariantClear(&id);
         if(!valid) throw std::runtime_error("shortcut activator missing");
         ks::registerScreenshotNotifications(); // Registration is safe to repeat.
+        bool launchFailed=false;
+        try { ks::startScreenshotNotificationRegistration(); }
+        catch(const std::exception &) { launchFailed=true; }
+        if(!launchFailed || activationExecutable!=helper.wstring() ||
+           activationCommand!=L"\""+helper.wstring()+L"\" --register-notifications" ||
+           !(launchFlags&CREATE_NO_WINDOW) || inheritsHandles)
+            throw std::runtime_error("registration must launch the sibling helper and propagate failure");
+        activationCalls=0;
         ks::Activator activator(helper.wstring(),false);
         activator.Activate(L"HrynCo.KSwitcher.Screenshot",L"check-update",nullptr,0);
         auto main=(helper.parent_path()/L"KSwitcher.exe").wstring();

tests/screenshot_ui.cpp

@@ -225,6 +225,17 @@ int main(int argc, char **argv)
             require(c.zoom>zoom && std::abs(before.x-after.x)<=1 && std::abs(before.y-after.y)<=1,
                     "Ctrl+wheel zoom keeps image point under cursor");
             require(!c.history.canUndo(),"zoom does not add image edits to undo history");
+            // A fixed zoom can still fit inside a high-DPI editor. Size the
+            // fixture from the actual viewport, with room for the tested drag
+            // on both axes, then start from a centered view.
+            const double panZoom=std::max({1.0,
+                double(c.canvas.right-c.canvas.left+128)/(c.view.right-c.view.left),
+                double(c.canvas.bottom-c.canvas.top+128)/(c.view.bottom-c.view.top)});
+            ks::zoomCanvas(window,c,panZoom,center);
+            c.panX=c.panY=0; ks::layout(window,c);
+            require(c.view.left+15<c.canvas.left && c.view.top+10<c.canvas.top &&
+                    c.view.right>c.canvas.right && c.view.bottom>c.canvas.bottom,
+                    "pan fixture has drag clearance on both axes within the supported zoom range");
             auto view=c.view;
             SendMessageW(window,WM_MBUTTONDOWN,MK_MBUTTON,MAKELPARAM(center.x,center.y));
             SendMessageW(window,WM_MOUSEMOVE,MK_MBUTTON,MAKELPARAM(center.x+15,center.y+10));
@@ -443,8 +454,16 @@ int main(int argc, char **argv)
             c.marks={{{20,20},{120,20},0}};
             require(ks::actionCursor(c,{0,ks::MarkPart::Body},true)==LoadCursorW(nullptr,IDC_SIZEALL),"move cursor overrides drawing tool");
             require(ks::actionCursor(c,{0,ks::MarkPart::Rotation},true)==LoadCursorW(nullptr,IDC_HAND),"rotation cursor overrides drawing tool");
-            require(ks::actionCursor(c,{0,ks::MarkPart::End},true)==LoadCursorW(nullptr,IDC_SIZEWE),"endpoint resize overrides drawing tool");
+            for(auto part:{ks::MarkPart::Start,ks::MarkPart::End,ks::MarkPart::Radius,
+                           ks::MarkPart::Label,ks::MarkPart::Vertex0,ks::MarkPart::Vertex1,ks::MarkPart::Vertex2})
+                require(ks::actionCursor(c,{0,part},true)==LoadCursorW(nullptr,IDC_SIZEALL),
+                        "freely movable handles use four-direction cursor for every drawing tool");
             require(ks::actionCursor(c,{0,ks::MarkPart::Thickness},true)==LoadCursorW(nullptr,IDC_SIZENS),"thickness resize is perpendicular to line");
+            c.marks[0].to={20,120};
+            require(ks::actionCursor(c,{0,ks::MarkPart::End},true)==LoadCursorW(nullptr,IDC_SIZEALL),
+                    "vertical line endpoint still moves in both axes");
+            require(ks::actionCursor(c,{0,ks::MarkPart::Thickness},true)==LoadCursorW(nullptr,IDC_SIZEWE),
+                    "vertical line thickness retains horizontal resize cursor");
         }
         c.marks.clear(); SendMessageW(window,WM_COMMAND,27,0);
         wchar_t windowTitle[128]{}; GetWindowTextW(window,windowTitle,128);

tests/tests.cpp

@@ -23,20 +23,6 @@ void rejects(const std::function<void()> &f, const char *name)
     bool thrown = false;
     try
     {
-        {
-            std::map<std::wstring,int> previews;
-            std::set<std::wstring> visible;
-            for(int i=0;i<40;++i) previews[std::to_wstring(i)]=i;
-            for(int i=0;i<8;++i) visible.insert(std::to_wstring(i));
-            ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==32,"preview cache stays bounded");
-            for(const auto &id:visible) require(previews.contains(id),"visible preview survives eviction");
-            for(int i=0;i<40;++i) { auto id=std::to_wstring(i); previews[id]=i; visible.insert(id); }
-            ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==40,"tall viewport does not thrash visible previews");
-            visible.clear(); ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==32,"cache shrinks after leaving tall viewport");
-        }
         f();
     }
     catch (...)
@@ -60,6 +46,34 @@ int main(int argc, char **argv)
     }
     try
     {
+        // Byte budgets must retain visible entries even when they alone exceed the budget.
+        {
+            std::map<std::wstring, size_t> cache{{L"a", 800}, {L"b", 800}, {L"c", 100}};
+            std::set<std::wstring> visible{L"b"};
+            auto weight=[](size_t bytes) { return bytes; };
+            ks::trimHistoryPreviews(cache, visible, 32, 1000, weight);
+            require(cache.size()==2 && cache.contains(L"b") && cache.contains(L"c"),
+                    "byte budget evicts offscreen previews below count limit");
+            ks::trimHistoryPreviews(cache, visible, 32, 100, weight);
+            require(cache.size()==1 && cache.contains(L"b"), "oversized visible preview never thrashes");
+            visible.clear();
+            ks::trimHistoryPreviews(cache, visible, 32, 100, weight);
+            require(cache.empty(), "oversized preview is freed after leaving viewport");
+        }
+        {
+            std::map<std::wstring,int> previews;
+            std::set<std::wstring> visible;
+            for(int i=0;i<40;++i) previews[std::to_wstring(i)]=i;
+            for(int i=0;i<8;++i) visible.insert(std::to_wstring(i));
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"preview cache stays bounded");
+            for(const auto &id:visible) require(previews.contains(id),"visible preview survives eviction");
+            for(int i=0;i<40;++i) { auto id=std::to_wstring(i); previews[id]=i; visible.insert(id); }
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==40,"tall viewport does not thrash visible previews");
+            visible.clear(); ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"cache shrinks after leaving tall viewport");
+        }
         {
             ks::DiagnosticJson record{{"attempt", "42"}, {"process", "editor.exe"}, {"command", "Convert / cycle"},
                 {"source", "English"}, {"target", "Ukrainian"}, {"outcome", "Original text remained"},
@@ -99,6 +113,10 @@ int main(int argc, char **argv)
                 "large diagnostic selections are explicitly truncated");
         STARTUPINFOW startup{sizeof(startup)};
         ks::DiagnosticBuffer diagnostics;
+        diagnostics.record(L"idle-expiry", false, 0);
+        require(diagnostics.expire(30000)==0,"diagnostics remain available at expiry boundary");
+        require(diagnostics.expire(30001)==1,"idle expiry releases context without another log event");
+        require(diagnostics.expire(60000)==0,"repeated idle expiry is safe");
         require(diagnostics.record(L"successful-attempt", false, 100).empty(),
                 "successful diagnostics stay in memory");
         auto incident = diagnostics.record(L"failed-attempt", true, 200);
@@ -217,6 +235,26 @@ int main(int argc, char **argv)
         require(!autoSettings.autoCorrect, "auto-correction defaults off");
         autoSettings.cycle = {L"en", L"uk"};
         corrector.configure(L"dictionaries", autoSettings.autoLanguages);
+        {
+            ks::AutoCorrector consumer;
+            consumer.shareDictionaries(corrector);
+            require(consumer.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "shared dictionaries produce the same correction");
+            consumer.reject(L"ghbdsn");
+            consumer.shareDictionaries(corrector);
+            require(!consumer.suggest(L"ghbdsn ", 0, layouts, autoSettings),
+                    "refreshing shared dictionaries preserves consumer undo rejections");
+            require(corrector.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "consumer rejections do not affect the predictor");
+            ks::AutoCorrector retained;
+            retained.shareDictionaries(corrector);
+            corrector.configure({}, {});
+            require(retained.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "in-flight dictionary snapshot survives source reset");
+            consumer.shareDictionaries(corrector);
+            require(consumer.memoryBytes() == 0, "disabled correction releases consumer dictionaries");
+            corrector.shareDictionaries(retained);
+        }
         {
             auto options = autoSettings;
             options.autoTypos = true;
@@ -545,6 +583,20 @@ int main(int argc, char **argv)
             require(!ambiguous.suggest(L"hell ", 0, layouts, options), "frequency filter does not conceal ambiguous typo targets");
         }
         ks::Pixels pixels{2, 1, {10, 20, 30, 255, 40, 50, 60, 255}};
+        {
+            auto png = ks::encodePng(pixels);
+            ks::Clip encoded{{{0, L"PNG", png}}};
+            for (int i=0; i<3; ++i) {
+                auto decoded=ks::decodeImage(encoded);
+                require(decoded.bgra==pixels.bgra && decoded.width==2 && decoded.height==1,
+                        "borrowed PNG stream preserves decoded pixels on repeated reads");
+                require(encoded.formats[0].data==png,"PNG decoder never modifies the borrowed input");
+            }
+            ks::Clip fallback{{{0,L"PNG",{}},ks::imageDib(pixels)}};
+            require(ks::decodeImage(fallback).bgra==pixels.bgra,"empty PNG falls back to DIB");
+            ks::Clip invalid{{{0,L"PNG",{1,2,3}}}};
+            rejects([&] { ks::decodeImage(invalid); },"invalid borrowed PNG fails safely");
+        }
         ks::Clip firstImage{{ks::imageDib(pixels), {0, L"Ole Private Data", {1, 2, 3}}}};
         auto thumbnail = ks::decodeImage(firstImage, 1, 1);
         require(thumbnail.width == 1 && thumbnail.height == 1 && thumbnail.bgra.size() == 4,

tools/measure-memory-components.ps1

@@ -0,0 +1,61 @@
+param([ValidateRange(1,20)][int]$Runs=3,[ValidateRange(100,10000)][int]$SettleMilliseconds=1500)
+# Private resident pages are counted externally, so the measurement buffer is
+# allocated in PowerShell, not in the measured process. Never trim working sets.
+$ErrorActionPreference='Stop'
+$root=Split-Path $PSScriptRoot -Parent
+$output=Join-Path $root 'build/memory-components'
+New-Item -ItemType Directory -Force $output | Out-Null
+$exe=Join-Path $output 'probe.exe'
+& "$root/.tools/w64devkit/bin/g++.exe" -std=c++20 -Os -static -s -DUNICODE -D_UNICODE -D_WIN32_WINNT=0x0A00 "$PSScriptRoot/memory-components.cpp" -o $exe -lole32 -loleaut32 -lshell32 -lpropsys -lshlwapi -luuid -luiautomationcore
+if($LASTEXITCODE) { throw 'Probe compilation failed' }
+Add-Type @'
+using System;
+using System.Runtime.InteropServices;
+public static class ComponentWorkingSet {
+ [DllImport("psapi.dll", SetLastError=true)] static extern bool QueryWorkingSet(IntPtr process,IntPtr buffer,int size);
+ public static long PrivateBytes(IntPtr process) {
+  int size=4*1024*1024;
+  IntPtr buffer=Marshal.AllocHGlobal(size);
+  try {
+   if(!QueryWorkingSet(process,buffer,size)) throw new System.ComponentModel.Win32Exception();
+   long count=Marshal.ReadIntPtr(buffer).ToInt64(), pages=0;
+   if(count>(size/IntPtr.Size)-1) throw new InvalidOperationException("Working set buffer is too small");
+   for(int i=0;i<count;i++) if((Marshal.ReadIntPtr(buffer,(i+1)*IntPtr.Size).ToInt64() & 256)==0) pages++;
+   return pages*Environment.SystemPageSize;
+  } finally { Marshal.FreeHGlobal(buffer); }
+ }
+}
+'@
+$rows=[Collections.Generic.List[object]]::new()
+foreach($run in 1..$Runs) {
+ foreach($mode in @('baseline','sta','mta','shell','uia','focused','combined')) {
+  $start=[Diagnostics.ProcessStartInfo]::new($exe,$mode)
+  $start.UseShellExecute=$false; $start.CreateNoWindow=$true
+  $start.RedirectStandardOutput=$true; $start.RedirectStandardInput=$true; $start.RedirectStandardError=$true
+  $process=[Diagnostics.Process]::Start($start)
+  $errors=$process.StandardError.ReadToEndAsync()
+  try {
+   foreach($expected in @('baseline','com','active','released','uninitialized')) {
+    $pending=$process.StandardOutput.ReadLineAsync()
+    if(!$pending.Wait(15000)) { throw "Timeout: $mode/$expected" }
+    $phase=$pending.Result
+    if($phase -ne $expected) { throw "Unexpected phase '$phase', expected $expected" }
+    Start-Sleep -Milliseconds $SettleMilliseconds
+    $process.Refresh()
+    $rows.Add([pscustomobject]@{Run=$run;Mode=$mode;Phase=$phase;PrivateBytes=$process.PrivateMemorySize64;PrivateWorkingSet=[ComponentWorkingSet]::PrivateBytes($process.Handle);WorkingSet=$process.WorkingSet64;Threads=$process.Threads.Count;Modules=@($process.Modules | ForEach-Object ModuleName)})
+    $process.StandardInput.Write("`n"); $process.StandardInput.Flush()
+   }
+   if(!$process.WaitForExit(15000)) { throw 'Exit timeout' }
+   if($process.ExitCode) { throw "Probe failed: $($errors.Result)" }
+   $errors.Result | Set-Content (Join-Path $output "$run-$mode.txt")
+  } finally {
+   if(!$process.HasExited) { $process.Kill(); $process.WaitForExit() }
+   $process.Dispose()
+   $rows | ConvertTo-Json -Depth 5 | Set-Content (Join-Path $output 'results.json')
+  }
+  Write-Host "Completed $run/$Runs $mode"
+ }
+}
+$rows | Group-Object Mode,Phase | ForEach-Object {
+ [pscustomobject]@{Case=$_.Name;PrivateMiB=[math]::Round(($_.Group.PrivateBytes | Measure-Object -Average).Average/1MB,3);PrivateWorkingSetMiB=[math]::Round(($_.Group.PrivateWorkingSet | Measure-Object -Average).Average/1MB,3)}
+} | Format-Table

tools/memory-components.cpp

@@ -0,0 +1,65 @@
+// Standalone attribution probe. No clipboard, registry or user input mutations.
+#include <windows.h>
+#include <shlobj.h>
+#include <propkey.h>
+#include <propvarutil.h>
+#include <uiautomation.h>
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+static void check(HRESULT hr) {
+    if (FAILED(hr)) { fprintf(stderr,"HRESULT=%08lx\n",(unsigned long)hr); exit(2); }
+}
+static void phase(const char *name) {
+    printf("%s\n",name); fflush(stdout);
+    if (getchar()==EOF) exit(3);
+}
+int main(int argc,char **argv) {
+    const char *mode=argc>1?argv[1]:"baseline";
+    const bool baseline=!strcmp(mode,"baseline");
+    const bool shell=!strcmp(mode,"shell") || !strcmp(mode,"combined");
+    const bool uia=!strcmp(mode,"uia") || !strcmp(mode,"focused") || !strcmp(mode,"combined");
+    phase("baseline");
+    if(!baseline) check(CoInitializeEx(nullptr,!strcmp(mode,"sta") || shell ? COINIT_APARTMENTTHREADED : COINIT_MULTITHREADED));
+    phase("com");
+    IShellLinkW *link{}; IPropertyStore *store{}; IPersistFile *file{};
+    IUIAutomation2 *automation{}; IUIAutomationElement *element{}; IUIAutomationTextPattern *pattern{};
+    wchar_t temporary[MAX_PATH]{},shortcut[MAX_PATH]{},exe[MAX_PATH]{};
+    if(shell) {
+        check(CoCreateInstance(CLSID_ShellLink,nullptr,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&link)));
+        GetModuleFileNameW(nullptr,exe,MAX_PATH);
+        check(link->SetPath(exe)); check(link->SetIconLocation(exe,0));
+        check(link->QueryInterface(IID_PPV_ARGS(&store)));
+        PROPVARIANT value{}; check(InitPropVariantFromString(L"KSwitcher.MemoryProbe",&value));
+        check(store->SetValue(PKEY_AppUserModel_ID,value)); PropVariantClear(&value);
+        GUID id{0xe3f78047,0xf0ad,0x49b6,{0x90,0x74,0x41,0x19,0x31,0x70,0x61,0x67}};
+        value.vt=VT_CLSID; value.puuid=&id;
+        check(store->SetValue(PKEY_AppUserModel_ToastActivatorCLSID,value)); check(store->Commit());
+        PWSTR programs{}; check(SHGetKnownFolderPath(FOLDERID_Programs,0,nullptr,&programs)); CoTaskMemFree(programs);
+        GetTempPathW(MAX_PATH,temporary); if(!GetTempFileNameW(temporary,L"ksm",0,shortcut)) return 4;
+        check(link->QueryInterface(IID_PPV_ARGS(&file))); check(file->Save(shortcut,TRUE));
+    }
+    if(uia) {
+        check(CoCreateInstance(CLSID_CUIAutomation8,nullptr,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&automation)));
+        check(automation->put_ConnectionTimeout(200)); check(automation->put_TransactionTimeout(200));
+        if(strcmp(mode,"uia")) {
+            HRESULT focused=automation->GetFocusedElement(&element);
+            fprintf(stderr,"focus=%08lx\n",(unsigned long)focused);
+            if(SUCCEEDED(focused) && element) {
+                BOOL password=TRUE,enabled=FALSE; CONTROLTYPEID type{};
+                element->get_CurrentIsPassword(&password); element->get_CurrentIsEnabled(&enabled); element->get_CurrentControlType(&type);
+                fprintf(stderr,"type=%d enabled=%d protected=%d\n",type,enabled,password);
+                if(!password) fprintf(stderr,"pattern=%08lx\n",(unsigned long)element->GetCurrentPatternAs(UIA_TextPatternId,IID_PPV_ARGS(&pattern)));
+            }
+        }
+    }
+    phase("active");
+    if(pattern) pattern->Release(); if(element) element->Release(); if(automation) automation->Release();
+    if(file) file->Release(); if(store) store->Release(); if(link) link->Release();
+    if(shortcut[0]) DeleteFileW(shortcut);
+    phase("released");
+    if(!baseline) { CoFreeUnusedLibrariesEx(0,0); CoUninitialize(); }
+    phase("uninitialized");
+    return 0;
+}