Fix crash with reload prompt in presence of modal dialog

When a modal dialog is open, we delay the opening of the reload prompt,
which is good.
We should not directly open the reload prompt while processing a focus
change signal, because that will interfere too much with the focus
itself. Queue the signal processing.

Fixes: QDS-381
Change-Id: I8973aa986de5a46bf874529cbbda0b325222fcac
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/coreplugin/documentmanager.cpp

@@ -215,7 +215,12 @@ void DocumentManagerPrivate::onApplicationFocusChange()
 
 DocumentManagerPrivate::DocumentManagerPrivate()
 {
-    connect(qApp, &QApplication::focusChanged, this, &DocumentManagerPrivate::onApplicationFocusChange);
+    // we do not want to do too much directly in the focus change event, so queue the connection
+    connect(qApp,
+            &QApplication::focusChanged,
+            this,
+            &DocumentManagerPrivate::onApplicationFocusChange,
+            Qt::QueuedConnection);
 }
 
 } // namespace Internal