Fixed webp gif animation lost on upload

[stromb0li]

Affected version

2.3 Beta 2

If you paste or upload a gif, the webp image does not honor the animation.

Repro step on XF website:
Make meme: https://imgflip.com/gif-maker/171218846/Oprah-You-Get-A-Car
Paste into XF editor
Post Thread.

Meme animation is now lost

 

[XF Bug Bot]

Thank you for reporting this issue, it has now been resolved. We are aiming to include any changes that have been made in a future XF release (2.3.0 Beta 3).

Change log:

Do not overwrite uploaded images when optimization fails and there are no other pending changes

There may be a delay before changes are rolled out to the XenForo Community.

 

[Jeremy P]

This is kind of subtle. We don't actually attempt WebP conversion for GIFs when using the GD image driver due to its lack of support for GIFs/animated WebP. However, it was being loaded into GD and saved back afterwards anyway, which caused the animation to be lost.

Note that GIFs which exceed the maximum dimensions will still lose their animation when resized with the GD image driver, which is unavoidable (and happens even in XF 2.2). Using Imagick should retain the animation (and convert to animated WebP, where enabled and supported).