Fatal error: Paletter image not supported by webp

[chimok]

Bug Description

I just tried to convert a existing site to webp with performance lab + modern image.

Steps to reproduce

1. Install and enable both plugins
2. Change setting to "webp"
3. Use wp-cli to regenerate all images: wp media regenerate
4. After a few images it stops with the error

Fatal error: Paletter image not supported by webp in /usr/www/users/xxxxxx/staging-xxxxxx-com/releases/20240924131521/wp-includes/class-wp-image-editor.php on line 592

Screenshots

Additional Context

• PHP Version: 8.1
• OS: Linux
• Browser: chromium
• Plugin Version: 3.4.1 / 2.2.0
• Device: Desktop

It seems the fix is to convert the image to RGB if it isn't already: https://stackoverflow.com/questions/39292617/fatal-error-paletter-image-not-supported-by-webp

[adamsilverstein]

Hey @chimok - thanks for the bug report and the link to a potential solution.

If you identified the image that the error is thrown on, can you upload it here as a testing artifact?

[chimok]

Hi @adamsilverstein, the image is from my customer. I'm not sure have the permission to share it here.

When I open the image with gimp I get this message, maybe that helps? It seems to be sRGB IEC61966-2.1
Anyway, I miss exception handling in your plugin. No matter what error it is, it should simply skip image instead exit the script.

[chimok]

@adamsilverstein Today I've got the idea to enable image magick on the server and try it again. I can confirm with image magick been able to convert almost all images. So this happens only with GD. If image magick is enabled, wordpress switch to it automatically. Anyway, with AVIF the script simply returned "Killed", I think that is because of old version of image magick.

Only regenerated 428 of 442 images (5 failed, 9 skipped).

[IlyaZha]

I have same errors with disabled image magick.
@adamsilverstein Image example:

[mytory]

The same error occurs with PNG files processed through https://tinypng.com/