fix: properly detach window delegate, check full screen enabled

src/MacVim/MMFullScreenWindow.m

@@ -136,6 +136,13 @@ - (void)enterFullScreen
 {
     ASLogDebug(@"Enter full-screen now");
 
+    // Detach the window delegate right now to prevent any stray resizing etc
+    // leading to undesired messages
+    NSWindowController *winController = [target windowController];
+    id delegate = [target delegate];
+    [winController setWindow:nil];
+    [target setDelegate:nil];
+
     // Hide Dock and menu bar when going to full screen. Only do so if the current screen
     // has a menu bar and dock.
     if ([self screenHasDockAndMenu]) {
@@ -162,13 +169,6 @@ - (void)enterFullScreen
     // this call so set the frame again just in case.
     [self setFrame:[[target screen] frame] display:NO];
 
-    // fool delegate
-    id delegate = [target delegate];
-    [target setDelegate:nil];
-
-    // make target's window controller believe that it's now controlling us
-    [[target windowController] setWindow:self];
-
     oldTabBarStyle = [[view tabBarControl] styleName];
 
     NSString *style =
@@ -181,7 +181,7 @@ - (void)enterFullScreen
     [view removeFromSuperviewWithoutNeedingDisplay];
     [[self contentView] addSubview:view];
     [self setInitialFirstResponder:[view textView]];
-    
+
     // NOTE: Calling setTitle:nil causes an exception to be raised (and it is
     // possible that 'target' has no title when we get here).
     if ([target title]) {
@@ -196,8 +196,10 @@ - (void)enterFullScreen
 
     [self setOpaque:[target isOpaque]];
 
+    // reassign target's window controller to believe that it's now controlling us
     // don't set this sooner, so we don't get an additional
-    // focus gained message  
+    // focus gained message
+    [winController setWindow:self];
     [self setDelegate:delegate];
 
     // Store view dimension used before entering full-screen, then resize the

src/MacVim/MMWindowController.m

@@ -1328,9 +1328,7 @@ - (void)windowDidResize:(id)sender
     // Calling setFrameSizeKeepGUISize: instead of setFrameSize: prevents a
     // degenerate case where frameSizeMayHaveChanged: ends up resizing the window
     // *again* causing windowDidResize: to be called.
-    if (fullScreenWindow == nil) {
-        [vimView setFrameSizeKeepGUISize:[self contentSize]];
-    } else {
+    if (fullScreenEnabled && fullScreenWindow != nil) {
         // Non-native full screen mode is more complicated and needs to
         // re-layout the Vim view to properly account for the menu bar / notch,
         // and misc fuopt configuration.
@@ -1342,6 +1340,9 @@ - (void)windowDidResize:(id)sender
         [vimView setFrameOrigin:desiredFrame.origin];
         [vimView setFrameSizeKeepGUISize:desiredFrame.size];
     }
+    else {
+        [vimView setFrameSizeKeepGUISize:[self contentSize]];
+    }
 }
 
 - (void)windowDidChangeBackingProperties:(NSNotification *)notification