[gtk/test-coverage: 3/7] png loader: gray can have alpha

[Matthias Clasen <matthiasc src gnome org>]

commit 14cb208ec209a944226709dea42788c043eb7982
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jul 15 23:07:59 2022 -0400

    png loader: gray can have alpha

 gdk/loaders/gdkpng.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gdk/loaders/gdkpng.c b/gdk/loaders/gdkpng.c
index 20711210d0..c049868caf 100644
--- a/gdk/loaders/gdkpng.c
+++ b/gdk/loaders/gdkpng.c
@@ -184,7 +184,8 @@ gdk_load_png (GBytes  *bytes,
   if (color_type == PNG_COLOR_TYPE_PALETTE)
     png_set_palette_to_rgb (png);
 
-  if (color_type == PNG_COLOR_TYPE_GRAY)
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
     png_set_expand_gray_1_2_4_to_8 (png);
 
   if (png_get_valid (png, info, PNG_INFO_tRNS))