Worked around a crash on Mac OS X 10.10 and earlier, thanks to Eric Wasylishen.
diff --git a/src/video/cocoa/SDL_cocoakeyboard.m b/src/video/cocoa/SDL_cocoakeyboard.m
index 2ad7bc3..91267e5 100644
--- a/src/video/cocoa/SDL_cocoakeyboard.m
+++ b/src/video/cocoa/SDL_cocoakeyboard.m
@@ -235,7 +235,12 @@ QuitHIDCallback()
IOHIDManagerUnscheduleFromRunLoop(s_hidManager, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
IOHIDManagerRegisterInputValueCallback(s_hidManager, NULL, NULL);
IOHIDManagerClose(s_hidManager, 0);
+
+#if 0 /* Releasing here causes a crash on Mac OS X 10.10 and earlier,
+ * so just leak it for now. See bug 2157 for details.
+ */
CFRelease(s_hidManager);
+#endif
s_hidManager = NULL;
}