Bug 1478347: Ensure that macOS-provided menu items are available in the Edit menu, especially in multi-language environments where Firefox may have a different language than the OS. r=mstange

Differential Revision: https://phabricator.services.mozilla.com/D193931

toolkit/xre/MacApplicationDelegate.mm

@@ -40,6 +40,7 @@
 #include "nsCommandLine.h"
 #include "nsStandaloneNativeMenu.h"
 #include "nsCocoaUtils.h"
+#include "nsMenuBarX.h"
 
 class AutoAutoreleasePool {
  public:
@@ -53,6 +54,11 @@ class AutoAutoreleasePool {
 @interface MacApplicationDelegate : NSObject <NSApplicationDelegate> {
 }
 
+// This is used as a workaround for bug 1478347 in order to make OS-provided
+// menu items such as the emoji picker available in the Edit menu, especially
+// in multi-language environments.
+- (IBAction)copy:(id)aSender;
+
 @end
 
 enum class LaunchStatus {
@@ -140,6 +146,10 @@ void ProcessPendingGetURLAppleEvents() {
 
 @implementation MacApplicationDelegate
 
+- (IBAction)copy:(id)aSender {
+  [nsMenuBarX::sNativeEventTarget menuItemHit:aSender];
+}
+
 - (id)init {
   NS_OBJC_BEGIN_TRY_BLOCK_RETURN;
 

widget/cocoa/nsMenuBarX.mm

@@ -536,7 +536,7 @@ void nsMenuBarX::MenuChildChangedVisibility(const MenuChild& aChild,
   NSMenuItem* item = child->NativeNSMenuItem();
   if (aIsVisible) {
     NSInteger insertionPoint = CalculateNativeInsertionPoint(child);
-    [mNativeMenu insertItem:child->NativeNSMenuItem() atIndex:insertionPoint];
+    [mNativeMenu insertItem:item atIndex:insertionPoint];
   } else if ([mNativeMenu indexOfItem:item] != -1) {
     [mNativeMenu removeItem:item];
   }

widget/cocoa/nsMenuItemX.mm

@@ -97,10 +97,22 @@ nsMenuItemX::nsMenuItemX(nsMenuX* aParent, const nsString& aLabel,
 
   mIsVisible = !nsMenuUtilsX::NodeIsHiddenOrCollapsed(mContent);
 
-  // All menu items share the same target and action, and are differentiated
-  // be a unique (representedObject, tag) pair.
-  mNativeMenuItem.target = nsMenuBarX::sNativeEventTarget;
-  mNativeMenuItem.action = @selector(menuItemHit:);
+  // All menu items other than the "Copy" menu item share the same target and
+  // action, and are differentiated be a unique (representedObject, tag) pair.
+  // The "Copy" menu item is a special case that requires a macOS-default
+  // action of `copy:` and a default target in order for the "Edit" menu to be
+  // populated with OS-provided menu items such as the Emoji picker,
+  // especially in multi-language environments (see bug 1478347). Our
+  // application delegate implements `copy:` by simply forwarding it to
+  // [nsMenuBarX::sNativeEventTarget menuItemHit:].
+  if (mContent->AsElement()->AttrValueIs(kNameSpaceID_None, nsGkAtoms::id,
+                                         u"menu_copy"_ns, eCaseMatters)) {
+    mNativeMenuItem.action = @selector(copy:);
+  } else {
+    mNativeMenuItem.action = @selector(menuItemHit:);
+    mNativeMenuItem.target = nsMenuBarX::sNativeEventTarget;
+  }
+
   mNativeMenuItem.representedObject = mMenuGroupOwner->GetRepresentedObject();
   mNativeMenuItem.tag = mMenuGroupOwner->RegisterForCommand(this);