SDL: SDL_ConvertSurface: clear sdl2-compat.surface2 on the converted surface

SDL Commits
1 
From 02c4478f9364ac9ba8c0b157c01e47c2f059552c Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 23 Oct 2025 08:23:56 +0300
Subject: [PATCH] SDL_ConvertSurface: clear sdl2-compat.surface2 on the
 converted surface

Fixes https://github.com/libsdl-org/sdl2-compat/issues/534
---
 src/video/SDL_surface.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index 914b1c63b6e99..9ae4f21586cbd 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -2153,6 +2153,9 @@ SDL_Surface *SDL_ConvertSurfaceAndColorspace(SDL_Surface *surface, SDL_PixelForm
         if (!SDL_CopyProperties(surface->props, SDL_GetSurfaceProperties(convert))) {
             goto error;
         }
+
+        // Make sure the new surface doesn't reference an old SDL2 surface.
+        SDL_ClearProperty(SDL_GetSurfaceProperties(convert), "sdl2-compat.surface2");
     }
 
     // We're ready to go!