From 39c8ebb0e912d072005771dc4f2317930c51c081 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Mon, 5 Aug 2024 07:03:18 -0700
Subject: [PATCH] Fixed handling of grayscale images with alpha

Fixes https://github.com/libsdl-org/SDL_image/issues/460
---
 src/IMG_png.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/IMG_png.c b/src/IMG_png.c
index 3d211d4c..d5bfebff 100644
--- a/src/IMG_png.c
+++ b/src/IMG_png.c
@@ -336,14 +336,14 @@ static void LIBPNG_LoadPNG_IO(SDL_IOStream *src, struct loadpng_vars *vars)
                 /* more than one transparent index, or translucency */
                 lib.png_set_expand(vars->png_ptr);
             }
+        } else if (color_type == PNG_COLOR_TYPE_GRAY) {
+            /* This will be turned into PNG_COLOR_TYPE_GRAY_ALPHA, so expand to RGBA */
+            lib.png_set_gray_to_rgb(vars->png_ptr);
         } else {
             ckey = 0; /* actual value will be set later */
         }
     }
 
-    if ( color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
-        lib.png_set_gray_to_rgb(vars->png_ptr);
-
     lib.png_read_update_info(vars->png_ptr, vars->info_ptr);
 
     lib.png_get_IHDR(vars->png_ptr, vars->info_ptr, &width, &height, &bit_depth,