From 6ffe686ba884b0ed4e9ed7ef14b0790050c82f82 Mon Sep 17 00:00:00 2001
From: Sergey Petrenko <just.gull@gmail.com>
Date: Wed, 22 Mar 2023 10:24:22 +0300
Subject: [PATCH] check keydown event characters length before returning the
 pressed character code

---
 modules/highgui/src/window_cocoa.mm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/highgui/src/window_cocoa.mm b/modules/highgui/src/window_cocoa.mm
index 1cf55f9397..2c05b10be5 100644
--- a/modules/highgui/src/window_cocoa.mm
+++ b/modules/highgui/src/window_cocoa.mm
@@ -618,7 +618,7 @@ CV_IMPL int cvWaitKey (int maxWait)
          inMode:NSDefaultRunLoopMode
          dequeue:YES];
 
-        if([event type] == NSKeyDown) {
+        if([event type] == NSKeyDown && [[event characters] length]) {
             returnCode = [[event characters] characterAtIndex:0];
             break;
         }