QCocoaMenu: Keep a reference to the containing menu item

This allows the menu to tell its containing item the menu got
deleted. This removes the need to reset the COCOA_MENU_ANCESTOR
property value, which would crash since QCocoaMenuItem::m_menu
would be a dangling pointer.

Task-number: QTBUG-41587
Change-Id: Ia3408ef85cf823bfddbc2c41d6534e43bf14ed29
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

4 files changed, 36 insertions, 3 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoamenu.h b/src/plugins/platforms/cocoa/qcocoamenu.h
index 3ee1dab84d..a05d2a4a38 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.h
+++ b/src/plugins/platforms/cocoa/qcocoamenu.h
@@ -94,6 +94,10 @@ public:
     QList<QCocoaMenuItem *> merged() const;
     void setMenuBar(QCocoaMenuBar *menuBar);
     QCocoaMenuBar *menuBar() const;
+
+    void setContainingMenuItem(QCocoaMenuItem *menuItem);
+    QCocoaMenuItem *containingMenuItem() const;
+
 private:
     QCocoaMenuItem *itemOrNull(int index) const;
     void insertNative(QCocoaMenuItem *item, QCocoaMenuItem *beforeItem);
@@ -106,6 +110,7 @@ private:
     bool m_visible;
     quintptr m_tag;
     QCocoaMenuBar *m_menuBar;
+    QCocoaMenuItem *m_containingMenuItem;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoamenu.mm b/src/plugins/platforms/cocoa/qcocoamenu.mm
index 3d0201e1a0..fcf670d0ef 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenu.mm
@@ -222,7 +222,8 @@ QCocoaMenu::QCocoaMenu() :
     m_enabled(true),
     m_visible(true),
     m_tag(0),
-    m_menuBar(0)
+    m_menuBar(0),
+    m_containingMenuItem(0)
 {
     m_delegate = [[QCocoaMenuDelegate alloc] initWithMenu:this];
     m_nativeItem = [[NSMenuItem alloc] initWithTitle:@"" action:nil keyEquivalent:@""];
@@ -238,6 +239,10 @@ QCocoaMenu::~QCocoaMenu()
         if (COCOA_MENU_ANCESTOR(item) == this)
             SET_COCOA_MENU_ANCESTOR(item, 0);
     }
+
+    if (m_containingMenuItem)
+        m_containingMenuItem->clearMenu(this);
+
     QCocoaAutoReleasePool pool;
     [m_nativeItem setSubmenu:nil];
     [m_nativeMenu release];
@@ -567,4 +572,14 @@ QCocoaMenuBar *QCocoaMenu::menuBar() const
     return m_menuBar;
 }
 
+void QCocoaMenu::setContainingMenuItem(QCocoaMenuItem *menuItem)
+{
+    m_containingMenuItem = menuItem;
+}
+
+QCocoaMenuItem *QCocoaMenu::containingMenuItem() const
+{
+    return m_containingMenuItem;
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoamenuitem.h b/src/plugins/platforms/cocoa/qcocoamenuitem.h
index 1efc9f9bfd..847064e6cf 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuitem.h
+++ b/src/plugins/platforms/cocoa/qcocoamenuitem.h
@@ -101,6 +101,7 @@ public:
     inline bool isSeparator() const { return m_isSeparator; }
 
     QCocoaMenu *menu() const { return m_menu; }
+    void clearMenu(QCocoaMenu *menu);
     MenuRole effectiveRole() const;
 
 private:
diff --git a/src/plugins/platforms/cocoa/qcocoamenuitem.mm b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
index 4b9a0146a9..f686c0a838 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuitem.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
@@ -131,13 +131,19 @@ void QCocoaMenuItem::setMenu(QPlatformMenu *menu)
 {
     if (menu == m_menu)
         return;
-    if (m_menu && COCOA_MENU_ANCESTOR(m_menu) == this)
-        SET_COCOA_MENU_ANCESTOR(m_menu, 0);
+
+    if (m_menu) {
+        if (COCOA_MENU_ANCESTOR(m_menu) == this)
+            SET_COCOA_MENU_ANCESTOR(m_menu, 0);
+        if (m_menu->containingMenuItem() == this)
+            m_menu->setContainingMenuItem(0);
+    }
 
     QCocoaAutoReleasePool pool;
     m_menu = static_cast<QCocoaMenu *>(menu);
     if (m_menu) {
         SET_COCOA_MENU_ANCESTOR(m_menu, this);
+        m_menu->setContainingMenuItem(this);
     } else {
         // we previously had a menu, but no longer
         // clear out our item so the nexy sync() call builds a new one
@@ -146,6 +152,12 @@ void QCocoaMenuItem::setMenu(QPlatformMenu *menu)
     }
 }
 
+void QCocoaMenuItem::clearMenu(QCocoaMenu *menu)
+{
+    if (menu == m_menu)
+        m_menu = 0;
+}
+
 void QCocoaMenuItem::setVisible(bool isVisible)
 {
     m_isVisible = isVisible;