[wp-trac] [WordPress Trac] #63152: Multi-file Uploader Triggers AVIF Upload Error Despite GD Support – WP_Image_Editor_Imagick Interference

[WordPress Trac]

#63152: Multi-file Uploader Triggers AVIF Upload Error Despite GD Support –
WP_Image_Editor_Imagick Interference
--------------------------+-----------------------------
 Reporter:  CyberCr33p    |      Owner:  (none)
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Media         |    Version:  6.7.2
 Severity:  normal        |   Keywords:
  Focuses:                |
--------------------------+-----------------------------
 **Environment:**

 - WordPress Version: [e.g., 6.7.2]
 - PHP Version: [e.g., 8.3.19]
 - Operating System: [FreeBSD]
 - GD extension: Compiled with AVIF support (IMG_AVIF defined and
 supported)
 - Imagick extension: Not built/installed

 **Description:**

 When uploading AVIF images via the multi-file uploader (plupload),
 WordPress rejects them with the error message:

 “This image cannot be processed by the web server. Convert it to JPEG or
 PNG before uploading.”

 Despite testing and confirming that GD fully supports AVIF (using a
 standalone PHP script, which shows that both imageavif() exists and
 imagetypes() includes the IMG_AVIF flag), the multi-file uploader still
 triggers the error. The underlying check in wp-includes/media.php is:

 {{{#!php
 // Check if AVIF images can be edited.
 if ( ! wp_image_editor_supports( array( 'mime_type' => 'image/avif' ) ) )
 {
     $defaults['avif_upload_error'] = true;
 }
 }}}

 It appears that WordPress is selecting the WP_Image_Editor_Imagick class
 from the default array:

 {{{#!php
 $implementations = apply_filters( 'wp_image_editors', array(
 'WP_Image_Editor_Imagick', 'WP_Image_Editor_GD' ) );
 }}}

 Even though Imagick isn’t actually built with PHP, its class is still
 present and is chosen over GD. This causes the AVIF support check to fail
 and the upload error to be triggered.

 **Steps to Reproduce:**

 1. Set up a WordPress environment where the PHP GD extension is compiled
 with AVIF support.
 2. Ensure that the Imagick extension is not installed.
 3. Attempt to upload an AVIF image using the multi-file uploader via the
 Media Library.
 4. Observe that the upload fails with the message: “This image cannot be
 processed by the web server. Convert it to JPEG or PNG before uploading.”

 **Expected Behavior:**

 WordPress should detect that GD supports AVIF images and select
 WP_Image_Editor_GD for image processing. The AVIF support check (using
 wp_image_editor_supports( array( 'mime_type' => 'image/avif' ) )) should
 return true, allowing AVIF images to be processed without error.

 **Actual Behavior:**

 The AVIF support check returns false because WordPress selects
 WP_Image_Editor_Imagick, which is not supported in my environment.
 Removing WP_Image_Editor_Imagick from the available editors (via the
 wp_image_editors filter) resolves the issue, indicating that the root
 cause is the editor selection process:

 {{{#!php
 add_filter( 'wp_image_editors', function( $editors ) {
     return array( 'WP_Image_Editor_GD' );
 });
 }}}

 **Conclusion:**

 It appears that WordPress incorrectly prioritizes WP_Image_Editor_Imagick
 for AVIF processing during multi-file uploads, even though GD is correctly
 reported as the active image editor in "Site Health." This leads to a
 false negative in the AVIF support check and prevents AVIF images from
 being processed.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/63152>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform