Cocoa: QColorDialog makes the application hang

The reason is that the color dialog is using a native dialog.
And this dialog enters modality on its own, bypassing the
modality mechanism in Qt. Most important, when the dialog leaves
modality, it does so by calling [NSApp stopModal]. And this call
stops all modal sessions in the application, including the ones
owned by Qt.

This patch detects when this situation occurs, and makes
sure that all modal sessions gets stopped the correct way, and
later rebuilt.

Rev-By: MortenS

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gui/kernel/qeventdispatcher_mac.mm b/src/gui/kernel/qeventdispatcher_mac.mm
index c9dd949..427f0b0 100644
--- a/src/gui/kernel/qeventdispatcher_mac.mm
+++ b/src/gui/kernel/qeventdispatcher_mac.mm
@@ -571,6 +571,12 @@ bool QEventDispatcherMac::processEvents(QEventLoop::ProcessEventsFlags flags)
                 QBoolBlocker execGuard(d->currentExecIsNSAppRun, false);
                 while (!d->interrupt && [NSApp runModalSession:session] == NSRunContinuesResponse)
                     qt_mac_waitForMoreModalSessionEvents();
+                if (!d->interrupt && session == d->currentModalSessionCached) {
+                    // Someone called e.g. [NSApp stopModal:] from outside the event
+                    // dispatcher (e.g to stop a native dialog). But that call wrongly stopped
+                    // 'session' as well. As a result, we need to restart all internal sessions:
+                    d->temporarilyStopAllModalSessions();
+                }
             } else {
                 d->nsAppRunCalledByQt = true;
                 QBoolBlocker execGuard(d->currentExecIsNSAppRun, true);