From ef54e0c4f4b73cf1339b7738d23dcbeebbc1d4ae Mon Sep 17 00:00:00 2001
From: Brian Collins <bri.l.collins@gmail.com>
Date: Sat, 16 Mar 2024 16:27:14 -0400
Subject: [PATCH] Workaround a macOS cursor-related bug.

This fixes an macOS bug that is only known to occur in fullscreen windows on the built-in displays of newer MacBooks with camera notches. When the mouse is moved near the top of such a window (within about 44 units) and then moved back down, the cursor rects aren't respected. This can cause the default cursor to be visible when it should not be.

(cherry picked from commit f1690e265e306818882c7c876a9e85492eeefa42)
---
 src/video/cocoa/SDL_cocoawindow.m | 36 +++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/src/video/cocoa/SDL_cocoawindow.m b/src/video/cocoa/SDL_cocoawindow.m
index b7ff1ca736..828366095c 100644
--- a/src/video/cocoa/SDL_cocoawindow.m
+++ b/src/video/cocoa/SDL_cocoawindow.m
@@ -460,6 +460,17 @@ static void Cocoa_UpdateClipCursor(SDL_Window * window)
     }
 }
 
+static NSCursor *Cocoa_GetDesiredCursor(void)
+{
+    SDL_Mouse *mouse = SDL_GetMouse();
+
+    if (mouse->cursor_shown && mouse->cur_cursor && !mouse->relative_mode) {
+        return (__bridge NSCursor *)mouse->cur_cursor->driverdata;
+    }
+
+    return [NSCursor invisibleCursor];
+}
+
 
 @implementation Cocoa_WindowListener
 
@@ -1323,6 +1334,7 @@ static int Cocoa_SendMouseButtonClicks(SDL_Mouse * mouse, NSEvent *theEvent, SDL
     NSPoint point;
     int x, y;
     SDL_Window *window;
+    NSView *contentView;
 
     if (!mouse) {
         return;
@@ -1330,6 +1342,17 @@ static int Cocoa_SendMouseButtonClicks(SDL_Mouse * mouse, NSEvent *theEvent, SDL
 
     mouseID = mouse->mouseID;
     window = _data.window;
+    contentView = _data.sdlContentView;
+    point = [theEvent locationInWindow];
+
+    if ([contentView mouse:[contentView convertPoint:point fromView:nil] inRect:[contentView bounds]] &&
+        [NSCursor currentCursor] != Cocoa_GetDesiredCursor()) {
+        // The wrong cursor is on screen, fix it. This fixes an macOS bug that is only known to
+        // occur in fullscreen windows on the built-in displays of newer MacBooks with camera
+        // notches. When the mouse is moved near the top of such a window (within about 44 units)
+        // and then moved back down, the cursor rects aren't respected.
+        [_data.nswindow invalidateCursorRectsForView:contentView];
+    }
 
     if ([self processHitTest:theEvent]) {
         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_HIT_TEST, 0, 0);
@@ -1340,7 +1363,6 @@ static int Cocoa_SendMouseButtonClicks(SDL_Mouse * mouse, NSEvent *theEvent, SDL
         return;
     }
 
-    point = [theEvent locationInWindow];
     x = (int)point.x;
     y = (int)(window->h - point.y);
 
@@ -1590,17 +1612,9 @@ static int Cocoa_SendMouseButtonClicks(SDL_Mouse * mouse, NSEvent *theEvent, SDL
 
 - (void)resetCursorRects
 {
-    SDL_Mouse *mouse;
     [super resetCursorRects];
-    mouse = SDL_GetMouse();
-
-    if (mouse->cursor_shown && mouse->cur_cursor && !mouse->relative_mode) {
-        [self addCursorRect:[self bounds]
-                     cursor:(__bridge NSCursor *)mouse->cur_cursor->driverdata];
-    } else {
-        [self addCursorRect:[self bounds]
-                     cursor:[NSCursor invisibleCursor]];
-    }
+    [self addCursorRect:[self bounds]
+                 cursor:Cocoa_GetDesiredCursor()];
 }
 
 - (BOOL)acceptsFirstMouse:(NSEvent *)theEvent