SDL: Fix duplicate event dispatch in Cocoa event pump (3cd5a)

SDL Commits
1 
From 3cd5a407b8a6e884d5f1dfba42651639a8aab20e Mon Sep 17 00:00:00 2001
From: Qiu Qiang <[EMAIL REDACTED]>
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.

(cherry picked from commit dd52dd8995dc1f0fb67e7ec8dcaa6c82416a7a4c)
---
 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 681c1a53a804f..f9e12cd11080d 100644
--- a/src/video/cocoa/SDL_cocoaevents.m
+++ b/src/video/cocoa/SDL_cocoaevents.m
@@ -97,6 +97,14 @@ - (void)sendEvent:(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];