bug#28692: Emacs fails to display images

[Ludovic Courtès]

Hello Diego,

Diego Nicola Barbato <address@hidden> skribis:

> Several of emacs image related features have stopped working properly:
> * Eww does not render images showing empty squares instead.
> * When visiting an image in a buffer and pressing n to visit the next
>   image the next image is either not displayed at all (showing an empty
>   square instead) or a thumbnail sized version is displayed.
> * Transformations such as "Fit to Window Width" or "Rotate Image" do not
>   work at all. The following error message is displayed instead:
>   ImageMagick error: no decode delegate for this image format `PBM' @
>   error/constitute.c/ReadImage/504
>   (This happens with all image formats not just .pbm)

Indeed, I experience this with DocView as well (when resizing), which
leads to:

  ImageMagick error: no decode delegate for this image format `PNG' @ 
error/constitute.c/ReadImage/504

Could it be a CLI change in ImageMagick?  The package was upgraded in
87a9c53b7ca08bd490c94fe5579c3f26c19be78c.

Ludo’.