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>

3 files changed, 41 insertions, 8 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);
 }
diff --git a/src/plugins/platforms/cocoa/qcocoamenuitem.mm b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
index e32ff26ff5..21f2b4de85 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuitem.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
@@ -288,7 +288,7 @@ NSMenuItem *QCocoaMenuItem::sync()
         }
 
         default:
-            qWarning() << "menu item" << m_text << "has unsupported role" << (int)m_role;
+            qWarning() << "Menu item" << m_text << "has unsupported role" << m_role;
         }
 
         if (mergeItem) {
diff --git a/tests/auto/widgets/widgets/qmenubar/tst_qmenubar.cpp b/tests/auto/widgets/widgets/qmenubar/tst_qmenubar.cpp
index 3a4c4545df..2c20d03066 100644
--- a/tests/auto/widgets/widgets/qmenubar/tst_qmenubar.cpp
+++ b/tests/auto/widgets/widgets/qmenubar/tst_qmenubar.cpp
@@ -132,6 +132,7 @@ private slots:
     void taskQTBUG53205_crashReparentNested();
 #ifdef Q_OS_MACOS
     void taskQTBUG56275_reinsertMenuInParentlessQMenuBar();
+    void QTBUG_57404_existingMenuItemException();
 #endif
 
     void platformMenu();
@@ -1539,6 +1540,32 @@ void tst_QMenuBar::taskQTBUG56275_reinsertMenuInParentlessQMenuBar()
 
     QVERIFY(tst_qmenubar_taskQTBUG56275(&menubar));
 }
+
+void tst_QMenuBar::QTBUG_57404_existingMenuItemException()
+{
+    QMainWindow mw1;
+    QMainWindow mw2;
+    mw1.show();
+    mw2.show();
+
+    QMenuBar *mb = new QMenuBar(&mw1);
+    mw1.setMenuBar(mb);
+    mb->show();
+    QMenu *editMenu = new QMenu(QLatin1String("Edit"), &mw1);
+    mb->addMenu(editMenu);
+    QAction *copyAction = editMenu->addAction("&Copy");
+    copyAction->setShortcut(QKeySequence("Ctrl+C"));
+    QTest::ignoreMessage(QtWarningMsg, "Menu item \"&Copy\" has unsupported role QPlatformMenuItem::MenuRole(NoRole)");
+    copyAction->setMenuRole(QAction::NoRole);
+
+    QVERIFY(QTest::qWaitForWindowExposed(&mw2));
+    QTest::qWait(100);
+    QTest::ignoreMessage(QtWarningMsg, "Menu item \"&Copy\" already in menu \"Edit\"");
+    mw2.close();
+    mw1.activateWindow();
+    QTest::qWait(100);
+    // No crash, all fine.
+}
 #endif // Q_OS_MACOS
 
 QTEST_MAIN(tst_QMenuBar)