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  1. Qt
  2. QTBUG-13237

Crash in QWidgetPrivate::unregisterOleDnd() when dropTarget->Release() decrements reference count to zero

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2: Important
    • Resolution: Done
    • Affects Version/s: 4.6.3, 4.7.4, 4.8.0
    • Fix Version/s: 4.8.6
    • Component/s: Widgets: Widgets and Dialogs
    • Labels:
      None
    • Environment:
      Windows XP, Windows Vista, Windows 7
    • Commits:
      871c2fbc5192836cc2918a760aec4d4c680fd8c0

      Description

      This is a duplicate of QTBUG-7801, but that bug was closed due to lack of activity.

      A crash will occur in QWidgetPrivate::unregisterOleDnd (\src\gui\kernel\qwidget_win.cpp) when the function attempts to call CoLockObjectExternal(dropTarget, false, true) if the dropTarget object's reference count was decremented to zero by the dropTarget->Release() call at the beginning of the function.

      I haven't been able to create a small project that can repro this issue, but I have attached a patch which fixes the problem for our project.

        Attachments

          Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-47737 Crash in QWindowsWindow::setDropSiteEnabled

          • P2: Important - Urgent, should be fixed, but will not stop the release.
          • Closed
          replaces

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-7801 QWidgetPrivate::unregisterOleDnd may delete the dropTarget without setting the pointer to null leading to a crash

          • Not Evaluated - Not yet evaluated/prioritized
          • Closed
          No reviews matched the request. Check your Options in the drop-down menu of this sections header.

            Activity

              People

              • Assignee:
                andysh Andy Shaw
                Reporter:
                hendo Neil Henderson
              • Votes:
                7 Vote for this issue
                Watchers:
                9 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved:

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