SDL: Disassociate the SDLOpenGLContext from the view before deleting it

SDL Commits
1 
From f5c0760c6bf465ffd9fcbb48ca0bcffa748c5d66 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 8 Mar 2023 01:15:21 -0800
Subject: [PATCH] Disassociate the SDLOpenGLContext from the view before
 deleting it

If we don't do this, the view will be blanked even if another context is current and rendering from that context won't be visible.

Fixes https://github.com/libsdl-org/SDL/issues/4986
---
 src/video/cocoa/SDL_cocoaopengl.h |  2 +-
 src/video/cocoa/SDL_cocoaopengl.m | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/video/cocoa/SDL_cocoaopengl.h b/src/video/cocoa/SDL_cocoaopengl.h
index d846d467526d..0bd549fc91e7 100644
--- a/src/video/cocoa/SDL_cocoaopengl.h
+++ b/src/video/cocoa/SDL_cocoaopengl.h
@@ -58,7 +58,7 @@ struct SDL_GLDriverData
 - (void)setWindow:(SDL_Window *)window;
 - (SDL_Window*)window;
 - (void)explicitUpdate;
-- (void)dealloc;
+- (void)cleanup;
 
 @property (retain, nonatomic) NSOpenGLPixelFormat* openglPixelFormat;  // macOS 10.10 has -[NSOpenGLContext pixelFormat] but this handles older OS releases.
 
diff --git a/src/video/cocoa/SDL_cocoaopengl.m b/src/video/cocoa/SDL_cocoaopengl.m
index b65d9b0e65c3..46a973a73d88 100644
--- a/src/video/cocoa/SDL_cocoaopengl.m
+++ b/src/video/cocoa/SDL_cocoaopengl.m
@@ -176,11 +176,10 @@ - (void)setWindow:(SDL_Window *)newWindow
             }
         }
     } else {
-        [self clearDrawable];
-        if (self == [NSOpenGLContext currentContext]) {
-            [self explicitUpdate];
+        if ([NSThread isMainThread]) {
+            [self setView:nil];
         } else {
-            [self scheduleUpdate];
+            dispatch_sync(dispatch_get_main_queue(), ^{ [self setView:nil]; });
         }
     }
 }
@@ -203,17 +202,22 @@ - (void)explicitUpdate
     }
 }
 
-- (void)dealloc
+- (void)cleanup
 {
+    [self setWindow:NULL];
+
     SDL_DelHintCallback(SDL_HINT_MAC_OPENGL_ASYNC_DISPATCH, SDL_OpenGLAsyncDispatchChanged, NULL);
     if (self->displayLink) {
         CVDisplayLinkRelease(self->displayLink);
+        self->displayLink = nil;
     }
     if (self->swapIntervalCond) {
         SDL_DestroyCond(self->swapIntervalCond);
+        self->swapIntervalCond = NULL;
     }
     if (self->swapIntervalMutex) {
         SDL_DestroyMutex(self->swapIntervalMutex);
+        self->swapIntervalMutex = NULL;
     }
 }
 
@@ -516,8 +520,9 @@ - (void)dealloc
 Cocoa_GL_DeleteContext(_THIS, SDL_GLContext context)
 { @autoreleasepool
 {
-    SDLOpenGLContext *nscontext = (SDLOpenGLContext *)CFBridgingRelease(context);
-    [nscontext setWindow:NULL];
+    SDLOpenGLContext *nscontext = (__bridge SDLOpenGLContext *)context;
+    [nscontext cleanup];
+    CFRelease(context);
 }}
 
 /* We still support OpenGL as long as Apple offers it, deprecated or not, so disable deprecation warnings about it. */