bug#69782: [PATCH] Fringe bitmaps should respect alpha-background

[Po Lu]

Nate Sandy <nsan@posteo.de> writes:

> Right. That in turn only gets called by
> {pgtk,x}_draw_image_glyph_string. I was unable to determine what those
> image glyphs are and how to create one, in order to observe whether this
> patch would be detrimental to them. However it does seem sensible for
> backgrounds to respect alpha-background here as well.

Unfortunately, preventing this are several omissions from our image
loading process, with the result that image transparency data from
images of most formats is lost once such images are processed into
instances of `struct image'.

> Where do these image glyphs get used? I didn't notice any difference
> with the images I tested (having applied this patch).

Any and all image glyphs should exercise this code, on Cairo that is.