From 76176486ced3a053f8afca6d96cbbbdc2248af56 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Thu, 14 Sep 2017 08:37:27 -0400
Subject: [PATCH] surface: Make sure SDL_ConvertSurface() deals with palettes
 (thanks, Sylvain!).

Fixes Bugzilla #3826.
Fixes Bugzilla #2979.
---
 src/video/SDL_pixels.c  | 2 +-
 src/video/SDL_surface.c | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/video/SDL_pixels.c b/src/video/SDL_pixels.c
index 13cd75abe..649303c58 100644
--- a/src/video/SDL_pixels.c
+++ b/src/video/SDL_pixels.c
@@ -658,7 +658,7 @@ SDL_SetPixelFormatPalette(SDL_PixelFormat * format, SDL_Palette *palette)
         return SDL_SetError("SDL_SetPixelFormatPalette() passed NULL format");
     }
 
-    if (palette && palette->ncolors != (1 << format->BitsPerPixel)) {
+    if (palette && palette->ncolors > (1 << format->BitsPerPixel)) {
         return SDL_SetError("SDL_SetPixelFormatPalette() passed a palette that doesn't match the format");
     }
 
diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index 678fdc291..600056fe9 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -998,6 +998,11 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
                                    surface->format->Gmask, surface->format->Bmask,
                                    surface->format->Amask);
 
+            /* Share the palette, if any */
+            if (surface->format->palette) {
+                SDL_SetSurfacePalette(tmp, surface->format->palette);
+            }
+            
             SDL_FillRect(tmp, NULL, surface->map->info.colorkey);
 
             tmp->map->info.flags &= ~SDL_COPY_COLORKEY;