cocoa: Properly set the pending fullscreen spaces state when in a transition

src/video/cocoa/SDL_cocoawindow.m

@@ -868,14 +868,16 @@ static NSCursor *Cocoa_GetDesiredCursor(void)
         return NO; // we only allow you to make a Space on fullscreen desktop windows.
     } else if (!state && window->last_fullscreen_exclusive_display) {
         return NO; // we only handle leaving the Space on windows that were previously fullscreen desktop.
-    } else if (state == isFullscreenSpace) {
+    } else if (state == isFullscreenSpace && !inFullscreenTransition) {
         return YES; // already there.
     }
 
     if (inFullscreenTransition) {
         if (state) {
+            [self clearPendingWindowOperation:PENDING_OPERATION_LEAVE_FULLSCREEN];
             [self addPendingWindowOperation:PENDING_OPERATION_ENTER_FULLSCREEN];
         } else {
+            [self clearPendingWindowOperation:PENDING_OPERATION_ENTER_FULLSCREEN];
             [self addPendingWindowOperation:PENDING_OPERATION_LEAVE_FULLSCREEN];
         }
         return YES;