bug#37153: 26.1; some png images scrambled

[Eli Zaretskii]

> Date: Sat, 24 Aug 2019 18:01:46 +0900
> From: mituharu@math.s.chiba-u.ac.jp
> Cc: 37153@debbugs.gnu.org, Paul Eggert <eggert@cs.ucla.edu>
> 
> I suspect there is a longstanding typo (or thinko) in PNG
> transparency handling code.
> 
>                                    YAMAMOTO Mitsuharu
>                               mituharu@math.s.chiba-u.ac.jp
> 
> diff --git a/src/image.c b/src/image.c
> index 81d8cb4e2b2..819e058f7e1 100644
> --- a/src/image.c
> +++ b/src/image.c
> @@ -6680,7 +6680,7 @@ png_load_body (struct frame *f, struct image *img,
> struct png_load_context *c)
>    /* Create an image and pixmap serving as mask if the PNG image
>       contains an alpha channel.  */
>    if (channels == 4
> -      && !transparent_p
> +      && transparent_p
>        && !image_create_x_image_and_pixmap (f, img, width, height, 1,
>                                          &mask_img, 1))
>      {
> 

That didn't change anything in how I see the image in question, FWIW.