From 437d78499cc2ce3f6f49a4efc9461ef1ada7a7b6 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Tue, 2 Sep 2025 21:18:55 -0700
Subject: [PATCH] Don't set SDL_SURFACE_LOCK_NEEDED until a surface is RLE
 encoded

Reference https://github.com/libsdl-org/sdl2-compat/issues/476
---
 src/video/SDL_RLEaccel.c | 6 ++++--
 src/video/SDL_blit.c     | 2 +-
 src/video/SDL_surface.c  | 4 ++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/video/SDL_RLEaccel.c b/src/video/SDL_RLEaccel.c
index 890b8250aa..2ca6d7e0db 100644
--- a/src/video/SDL_RLEaccel.c
+++ b/src/video/SDL_RLEaccel.c
@@ -1434,6 +1434,7 @@ bool SDL_RLESurface(SDL_Surface *surface)
 
     // The surface is now accelerated
     surface->internal_flags |= SDL_INTERNAL_SURFACE_RLEACCEL;
+    SDL_UpdateSurfaceLockFlag(surface);
 
     return true;
 }
@@ -1565,11 +1566,12 @@ void SDL_UnRLESurface(SDL_Surface *surface, bool recode)
                 }
             }
         }
-        surface->map.info.flags &=
-            ~(SDL_COPY_RLE_COLORKEY | SDL_COPY_RLE_ALPHAKEY);
+        surface->map.info.flags &= ~(SDL_COPY_RLE_COLORKEY | SDL_COPY_RLE_ALPHAKEY);
 
         SDL_free(surface->map.data);
         surface->map.data = NULL;
+
+        SDL_UpdateSurfaceLockFlag(surface);
     }
 }
 
diff --git a/src/video/SDL_blit.c b/src/video/SDL_blit.c
index 5ffd1814e6..860a2a9bc2 100644
--- a/src/video/SDL_blit.c
+++ b/src/video/SDL_blit.c
@@ -191,7 +191,7 @@ bool SDL_CalculateBlit(SDL_Surface *surface, SDL_Surface *dst)
 
 #ifdef SDL_HAVE_RLE
     // Clean everything out to start
-    if (surface->flags & SDL_INTERNAL_SURFACE_RLEACCEL) {
+    if (surface->internal_flags & SDL_INTERNAL_SURFACE_RLEACCEL) {
         SDL_UnRLESurface(surface, true);
     }
 #endif
diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index dc897fbab9..7fe2542f76 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -49,7 +49,7 @@ bool SDL_SurfaceValid(SDL_Surface *surface)
 
 void SDL_UpdateSurfaceLockFlag(SDL_Surface *surface)
 {
-    if (SDL_SurfaceHasRLE(surface)) {
+    if (surface->internal_flags & SDL_INTERNAL_SURFACE_RLEACCEL) {
         surface->flags |= SDL_SURFACE_LOCK_NEEDED;
     } else {
         surface->flags &= ~SDL_SURFACE_LOCK_NEEDED;
@@ -611,7 +611,6 @@ bool SDL_SetSurfaceRLE(SDL_Surface *surface, bool enabled)
     if (surface->map.info.flags != flags) {
         SDL_InvalidateMap(&surface->map);
     }
-    SDL_UpdateSurfaceLockFlag(surface);
     return true;
 }
 
@@ -1760,6 +1759,7 @@ bool SDL_LockSurface(SDL_Surface *surface)
         if (surface->internal_flags & SDL_INTERNAL_SURFACE_RLEACCEL) {
             SDL_UnRLESurface(surface, true);
             surface->internal_flags |= SDL_INTERNAL_SURFACE_RLEACCEL; // save accel'd state
+            SDL_UpdateSurfaceLockFlag(surface);
         }
 #endif
     }