Cocoa: p1 bug fix: fix auto test regressions

Ref: 32228c4f2b3419a35d1623377050ef72edf73c92
It seems that the change above broke some auto tests, which
revealed a true problem. When it comes to modal dialog, children
still needs to be stacked on top of modal parents, as they the
user cannot use the mouse to raise it. So rather than removing
subWindowStacking fully, we narrow it even further down to
only be used for children of modal dialogs. All in all, this
is close to removing it, but still us it for certain corner cases.

Task-number: QTBUG-11481
Reviewed-by: msorvig

1 files changed, 10 insertions, 5 deletions

diff --git a/src/gui/kernel/qwidget_mac.mm b/src/gui/kernel/qwidget_mac.mm
index 0f4abfa..aca1d53 100644
--- a/src/gui/kernel/qwidget_mac.mm
+++ b/src/gui/kernel/qwidget_mac.mm
@@ -2795,11 +2795,9 @@ void QWidgetPrivate::transferChildren()
 void QWidgetPrivate::setSubWindowStacking(bool set)
 {
     // After hitting too many unforeseen bugs trying to put Qt on top of the cocoa child
-    // window API, we have decided to revert this behaviour. For compability
-    // reasons we leave the code here for applications depending on it:
+    // window API, we have decided to revert this behaviour as much as we can. We
+    // therefore now only allow child windows to exist for children of modal dialogs.
     static bool use_behaviour_qt473 = !qgetenv("QT_MAC_USE_CHILDWINDOWS").isEmpty();
-    if (use_behaviour_qt473 == false)
-        return;
 
     // This will set/remove a visual relationship between parent and child on screen.
     // The reason for doing this is to ensure that a child always stacks infront of
@@ -2829,7 +2827,10 @@ void QWidgetPrivate::setSubWindowStacking(bool set)
         if (NSWindow *pwin = [qt_mac_nativeview_for(parent) window]) {
             if (set) {
                 Qt::WindowType ptype = parent->window()->windowType();
-                if ([pwin isVisible] && (ptype == Qt::Window || ptype == Qt::Dialog) && ![qwin parentWindow]) {
+                if ([pwin isVisible]
+                    && (ptype == Qt::Window || ptype == Qt::Dialog)
+                    && ![qwin parentWindow]
+                    && (!use_behaviour_qt473 && parent->windowModality() == Qt::ApplicationModal)) {
                     NSInteger level = [qwin level];
                     [pwin addChildWindow:qwin ordered:NSWindowAbove];
                     if ([qwin level] < level)
@@ -2841,6 +2842,10 @@ void QWidgetPrivate::setSubWindowStacking(bool set)
         }
     }
 
+    // Only set-up child windows for q if q is modal:
+    if (set && !use_behaviour_qt473 && q->windowModality() != Qt::ApplicationModal)
+        return;
+
     QObjectList widgets = q->children();
     for (int i=0; i<widgets.size(); ++i) {
         QWidget *child = qobject_cast<QWidget *>(widgets.at(i));