QCocoaMenu: Avoid exception when inserting item already in this menu

This should not happen, but it's clearly not the user's fault.
So we should try to carry on as gracefully as possible instead
of letting Cocoa abort the application.

The patch also factors the repeated calls to QCocoaMenuItem::
nsItem() in QCocoaMenu::insertNative() and improves a warning
from QCocoaMenuIten::sync().

Change-Id: Id00135c219aaf40fb565b19a65cab68f6d9863b2
Task-number: QTBUG-57404
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 13 insertions, 7 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoamenu.mm b/src/plugins/platforms/cocoa/qcocoamenu.mm
index 88ffd48538..915463a52a 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenu.mm
@@ -331,11 +331,12 @@ void QCocoaMenu::insertMenuItem(QPlatformMenuItem *menuItem, QPlatformMenuItem *
 
 void QCocoaMenu::insertNative(QCocoaMenuItem *item, QCocoaMenuItem *beforeItem)
 {
-    item->nsItem().target = m_nativeMenu.delegate;
-    item->nsItem().action = @selector(itemFired:);
+    NSMenuItem *nativeItem = item->nsItem();
+    nativeItem.target = m_nativeMenu.delegate;
+    nativeItem.action = @selector(itemFired:);
     // Someone's adding new items after aboutToShow() was emitted
-    if (isOpen() && item->menu() && item->nsItem())
-        item->menu()->setAttachedItem(item->nsItem());
+    if (isOpen() && nativeItem)
+        item->menu()->setAttachedItem(nativeItem);
 
     item->setParentEnabled(isEnabled());
 
@@ -348,15 +349,20 @@ void QCocoaMenu::insertNative(QCocoaMenuItem *item, QCocoaMenuItem *beforeItem)
         beforeItem = itemOrNull(m_menuItems.indexOf(beforeItem) + 1);
     }
 
+    if (nativeItem.menu) {
+        qWarning() << "Menu item" << item->text() << "already in menu" << QString::fromNSString(nativeItem.menu.title);
+        return;
+    }
+
     if (beforeItem) {
         if (beforeItem->isMerged()) {
             qWarning("No non-merged before menu item found");
             return;
         }
-        NSUInteger nativeIndex = [m_nativeMenu indexOfItem:beforeItem->nsItem()];
-        [m_nativeMenu insertItem: item->nsItem() atIndex: nativeIndex];
+        const NSInteger nativeIndex = [m_nativeMenu indexOfItem:beforeItem->nsItem()];
+        [m_nativeMenu insertItem:nativeItem atIndex:nativeIndex];
     } else {
-        [m_nativeMenu addItem: item->nsItem()];
+        [m_nativeMenu addItem:nativeItem];
     }
     item->setMenuParent(this);
 }