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

src/app.cpp

@@ -358,6 +358,14 @@ class Transaction
         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();
@@ -433,6 +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();
@@ -1893,6 +1902,14 @@ 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;
@@ -2012,7 +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;