Do not send clipboard message to application under debugger.

Fix Qt Creator hang when copying a stack trace from an
application showing a runtime assert.

Change-Id: I874bd48643ebce1a3551644dc850cb7cf5869522
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
(cherry picked from qtbase/333817b9cf1304cca7c1dbd45880115cd128f60e)

1 files changed, 22 insertions, 0 deletions

diff --git a/src/gui/kernel/qclipboard_win.cpp b/src/gui/kernel/qclipboard_win.cpp
index 4ac59ef..5c36c09 100644
--- a/src/gui/kernel/qclipboard_win.cpp
+++ b/src/gui/kernel/qclipboard_win.cpp
@@ -300,6 +300,24 @@ void QClipboard::clear(Mode mode)
 #endif
 }
 
+#if !defined(Q_OS_WINCE) && defined(Q_CC_MSVC)
+static bool isProcessBeingDebugged(HWND hwnd)
+{
+    DWORD pid = 0;
+    if (!GetWindowThreadProcessId(hwnd, &pid) || !pid)
+        return false;
+    const HANDLE processHandle = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);
+    if (!processHandle)
+       return false;
+    BOOL debugged = FALSE;
+    CheckRemoteDebuggerPresent(processHandle, &debugged);
+    CloseHandle(processHandle);
+    return debugged != FALSE;
+}
+#else // !defined(Q_OS_WINCE) && defined(Q_CC_MSVC)
+static bool isProcessBeingDebugged(HWND) { return false; }
+#endif // defined(Q_OS_WINCE) || !defined(Q_CC_MSVC)
+
 bool QClipboard::event(QEvent *e)
 {
     if (e->type() != QEvent::Clipboard)
@@ -338,6 +356,10 @@ bool QClipboard::event(QEvent *e)
         }
         if (ptrIsHungAppWindow && ptrIsHungAppWindow(d->nextClipboardViewer)) {
             qWarning("%s: Cowardly refusing to send clipboard message to hung application...", Q_FUNC_INFO);
+        } else if (isProcessBeingDebugged(d->nextClipboardViewer)) {
+            // Also refuse if the process is being debugged, specifically, if it is
+            // displaying a runtime assert, which is not caught by isHungAppWindow().
+            qWarning("%s: Cowardly refusing to send clipboard message to application under debugger...", Q_FUNC_INFO);
         } else {
             SendMessage(d->nextClipboardViewer, m->message, m->wParam, m->lParam);
         }