[gdk-pixbuf: 1/2] gif: Fix bug where the local colormap is not dropped.

[Emmanuele Bassi <ebassi src gnome org>]

commit 7d1f42d204433ab7585d16202592b8f4d8d9e4eb
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Jul 14 14:26:18 2020 +1200

    gif: Fix bug where the local colormap is not dropped.
    
    This was seen in a GIF file that had a local colormap set on frame 6, but not
    on frame 7. Instead of reverting to the global colormap we continued to render
    with the last local colormap.
    
    This was a regression introduced in 4e7b5345d2fc8f0d1dee93d8ba9ab805bc95d42f.
    
    Fixes https://gitlab.gnome.org/GNOME/gdk-pixbuf/-/issues/156

 gdk-pixbuf/io-gif.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/gdk-pixbuf/io-gif.c b/gdk-pixbuf/io-gif.c
index 38ec03d7b3..2a7afd049d 100644
--- a/gdk-pixbuf/io-gif.c
+++ b/gdk-pixbuf/io-gif.c
@@ -112,7 +112,6 @@ struct _GifContext
        unsigned int global_color_resolution;
         unsigned int background_index;
 
-        gboolean frame_cmap_active;
         CMap frame_color_map;
         gint frame_colormap_size;
         unsigned int frame_bit_pixel;
@@ -234,7 +233,6 @@ gif_set_get_colormap (GifContext *context)
 static void
 gif_set_get_colormap2 (GifContext *context)
 {
-       context->frame_colormap_size = 0;
        context->state = GIF_GET_COLORMAP2;
 }
 
@@ -696,6 +694,7 @@ gif_get_frame_info (GifContext *context)
                  context->gif89.disposal, context->gif89.delay_time, context->gif89.transparent, 
context->frame_interlace);
 #endif
         
+       context->frame_colormap_size = 0;
        if (BitSet (buf[8], LOCALCOLORMAP)) {
 
 #ifdef DUMP_IMAGE_DETAILS
@@ -707,7 +706,6 @@ gif_get_frame_info (GifContext *context)
                 * of an animated gif. */
                /* if it does, we need to re-read in the colormap,
                 * the gray_scale, and the bit_pixel */
-                context->frame_cmap_active = TRUE;
                context->frame_bit_pixel = 1 << ((buf[8] & 0x07) + 1);
                gif_set_get_colormap2 (context);
                return 0;