Fix check for whether frames fit into gif images

* src/image.c (gif_load): Really check all frames that they fit.

1 files changed, 7 insertions, 4 deletions

diff --git a/src/image.c b/src/image.c
index b6edcf96a0b..3afb8324078 100644
--- a/src/image.c
+++ b/src/image.c
@@ -8937,16 +8937,19 @@ gif_load (struct frame *f, struct image *img)
 
       /* Check that the selected subimages fit.  It's not clear whether
          the GIF spec requires this, but Emacs can crash if they don't fit.  */
-      for (j = 0; j <= idx; ++j)
+      for (j = 0; j < gif->ImageCount; ++j)
         {
           struct SavedImage *subimage = gif->SavedImages + j;
           int subimg_width = subimage->ImageDesc.Width;
           int subimg_height = subimage->ImageDesc.Height;
           int subimg_top = subimage->ImageDesc.Top;
           int subimg_left = subimage->ImageDesc.Left;
-          if (! (subimg_width >= 0 && subimg_height >= 0
-                 && 0 <= subimg_top && subimg_top <= height - subimg_height
-                 && 0 <= subimg_left && subimg_left <= width - subimg_width))
+          if (subimg_width < 0
+              || subimg_height < 0
+              || subimg_top < 0
+              || subimg_left < 0
+              || subimg_top + subimg_height > height
+              || subimg_left + subimg_width > width)
             {
               image_error ("Subimage does not fit in image");
               goto gif_error;