cocoa: fix segfault in certain circumstances

i falsely assumed that the windowDidChangeScreen was meant to report
‘physical’ screen changes but was wondering why it triggers on other
events too. it actually is a event that informs us when anything
referenced by our current NSScreen is changed. even when something
referenced in the NSScreen changed the old and new NSScreen are still
equal if the physical screen didn’t change. with that my previous
optimisation broke some cases where the physical screen didn’t change
but things it referenced did, leading to a segfault when theses were
accessed. to keep the optimisation we will always update our internal
NSScreen reference but the rest only when the physical screen was
changed.

video/out/cocoa/mpvadapter.h

@@ -28,6 +28,7 @@
 - (void)handleFilesArray:(NSArray *)files;
 - (void)didChangeWindowedScreenProfile:(NSNotification *)notification;
 - (void)performAsyncResize:(NSSize)size;
+- (void)windowDidChangePhysicalScreen;
 
 - (BOOL)isInFullScreenMode;
 - (BOOL)keyboardEnabled;

video/out/cocoa/window.m

@@ -168,14 +168,15 @@
 
 - (void)windowDidChangeScreen:(NSNotification *)notification
 {
-    //this event doesn't exclusively trigger on screen change
-    //examples: screen reconfigure, toggling fullscreen
+    [self.adapter windowDidChangeScreen:notification];
+
     if (!_is_animating && ![[self currentScreen] isEqual:[self screen]]) {
         self.previousScreen = [self screen];
     }
     if (![[self currentScreen] isEqual:[self screen]]) {
-        [self.adapter windowDidChangeScreen:notification];
+        [self.adapter windowDidChangePhysicalScreen];
     }
+
     self.currentScreen = [self screen];
 }
 

video/out/cocoa_common.m

@@ -1018,6 +1018,10 @@ int vo_cocoa_control(struct vo *vo, int *events, int request, void *arg)
 - (void)windowDidChangeScreen:(NSNotification *)notification
 {
     vo_cocoa_update_screen_info(self.vout);
+}
+
+- (void)windowDidChangePhysicalScreen
+{
     vo_cocoa_update_displaylink(self.vout);
     flag_events(self.vout, VO_EVENT_WIN_STATE);
 }