WP_Customize_Media_Control default webp

[buutqn]

Class WP_Customize_Media_Control, in function to_json, ignores different number of characters for extensions, ignoring those extensions that has 4 characters.
​https://github.com/WordPress/wordpress-develop/blob/6.9/src/wp-includes/customize/class-wp-customize-media-control.php#L95-L96

Line 95 will not return "webp" or "avif":

$ext  = substr( $this->setting->default, -3 );

Fix WP_Customize_Media_Control::to_json() extension validation.

Trac ticket: #64557

[buutqn]

Should we simplify?

$ext = pathinfo( $this->setting->default, PATHINFO_EXTENSION );

[westonruter]

Good catch. This certainly can be made more robust.

The use of substr() was introduced in r30309 (​4175d8a). But the actual issue was introduced in r50810 (for #35725) to add WebP support and similarly in r57524 (for #51228) to add AVIF support, as these two file formats use 4-character file file extensions.

Note: In the future, it would be preferable to open a pull request to target trunk rather than the current release branch.

Previously:

• ​https://github.com/WordPress/wordpress-develop/pull/10803

Trac ticket: https://core.trac.wordpress.org/ticket/64557#ticket

Closing in favor of ​https://github.com/WordPress/wordpress-develop/pull/10842

[westonruter]

In 61576:

Customize: Use wp_check_filetype() instead of substr() to extract file extension.

This fixes compatibility with image files that have 4-character extensions, such as .webp and .avif.

Follow-up to [57524], [50810], [30309].

Props buutqn, westonruter.
See #51228, #35725, #21483.
Fixes #64557.