GIF support may be going away on Linux using GDK in the future

[jonahgraham]

Describe the bug

On Linux, the GTK port uses gdk-pixbuf to decode image files. The gdk-pixbuf maintainers consider gif (and a few other formats) "fringe" and are looking to not support them anymore in the future. See this PR in gdk-pixbuf. For now gdk-pixbuf have simply disabled them by default, and we are relying on Distros to make them enabled. In the future they may split gif handling into a new package for distros.

The first version of gdk-pixbuf that changed this default is 2.42.11(versions >= 2.24.11 can still include gif support though)

Please see eclipse-packaging/packages#187 for more background.

To Reproduce

Not 100% sure how to reproduce, but opening gif files on a system with the missing decoder would do it.

Screenshots

See eclipse-packaging/packages#187 (comment) for screenshots and logs.

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

Linux only, but see above description for additional environmental info.

Workaround (or) Additional context

Long term Eclipse may need to resolve gif support if it gets dropped fully. This seems unlikely in the near term. If it does get dropped, there are ~32K gif files in SimRel. It may be simpler to have a fallback Java based gif loader rather than expect all projects to change.

I have created this issue here to ensure that SWT maintainers are aware of the potential problem. We are not sure that the user in eclipse-packaging/packages#187 actually hit this problem or some other issue due to configuration in their Linux install. Their problem was resolved with a distro re-install.

[akurtakov]

I can't even imagine Linux distro without support for gif files aka there might be some temp issues like the one seen one but they will (hopefully!) be resolved before this hits an LTS release. At least that's my hope!

[Phillipus]

A user of our RCP app ran into this on NixOS with bmp files so it can happen. I replaced the files with png files but can't guarantee that some underlying parts of Eclipse use gif. So not just a problem for Eclipse, but also RCP apps.

[laeubi]

SWT already has GIFFileFormat (among others), so for me it seems more an issue of that we need to detect that an image format is not supported and then fall back to the "non native" java counterparts?