Crash when deleting QMainWindow with native toolbar on Cocoa.

The crash happens while processing a paint message received by the
NSToolbar after the corresponding QToolbar has been destroyed. So while
cleaning up the toolbar, the view needs to be detached from the custom
toolbar item.

Task-number: QTBUG-7305
Reviewed-by: Carlos Manuel Duclos Vergara

1 files changed, 9 insertions, 3 deletions

diff --git a/src/gui/widgets/qmainwindowlayout_mac.mm b/src/gui/widgets/qmainwindowlayout_mac.mm
index ee79f5a..d92168a 100644
--- a/src/gui/widgets/qmainwindowlayout_mac.mm
+++ b/src/gui/widgets/qmainwindowlayout_mac.mm
@@ -472,14 +472,20 @@ void QMainWindowLayout::removeFromMacToolbar(QToolBar *toolbar)
 
 void QMainWindowLayout::cleanUpMacToolbarItems()
 {
-    for (int i = 0; i < toolbarItemsCopy.size(); ++i)
+#ifdef QT_MAC_USE_COCOA
+    QMacCocoaAutoReleasePool pool;
+#endif
+    for (int i = 0; i < toolbarItemsCopy.size(); ++i) {
+#ifdef QT_MAC_USE_COCOA
+        NSToolbarItem *item = static_cast<NSToolbarItem *>(toolbarItemsCopy.at(i));
+        [item setView:0];
+#endif
         CFRelease(toolbarItemsCopy.at(i));
+    }
     toolbarItemsCopy.clear();
     unifiedToolbarHash.clear();
 
 #ifdef QT_MAC_USE_COCOA
-    QMacCocoaAutoReleasePool pool;
-
     OSWindowRef window = qt_mac_window_for(layoutState.mainWindow);
     NSToolbar *macToolbar = [window toolbar];
     if (macToolbar) {