From dd52dd8995dc1f0fb67e7ec8dcaa6c82416a7a4c Mon Sep 17 00:00:00 2001
From: Qiu Qiang <qqiu@qiuleyan.com>
Date: Sun, 11 Jan 2026 21:31:14 -0500
Subject: [PATCH] Fix duplicate event dispatch in Cocoa event pump

Prevent mouse and keyboard events from being processed twice by
skipping [super sendEvent:] for events SDL has already handled via
Cocoa_DispatchEvent. Other event types still go through AppKit's
normal handling.
---
 src/video/cocoa/SDL_cocoaevents.m | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/video/cocoa/SDL_cocoaevents.m b/src/video/cocoa/SDL_cocoaevents.m
index 681c1a53a8..f9e12cd110 100644
--- a/src/video/cocoa/SDL_cocoaevents.m
+++ b/src/video/cocoa/SDL_cocoaevents.m
@@ -97,6 +97,14 @@ static void Cocoa_DispatchEvent(NSEvent *theEvent)
 {
     if (s_bShouldHandleEventsInSDLApplication) {
         Cocoa_DispatchEvent(theEvent);
+
+        // Avoid double-dispatching mouse and keyboard events. They are already handled in Cocoa_DispatchEvent.
+        // Other event types should still go through AppKit's normal handling.
+        NSEventType type = [theEvent type];
+        if ((type >= NSEventTypeLeftMouseDown && type <= NSEventTypeMouseExited) ||
+            (type >= NSEventTypeKeyDown && type <= NSEventTypeFlagsChanged)) {
+            return;
+        }
     }
 
     [super sendEvent:theEvent];