wp_create_file_in_uploads Called as Action Hook

[Howdy_McGee]

The ​wp_create_file_in_uploads hook is labeled as an Action Hook in the docs but is actually called multiple times as a Filter Hook.

As an Action Hook: ​class-custom-image-header.php

As a Filter Hook: ​ajax-actions.php, ​class-custom-image-header.php (and more)

To keep the docs accurate, this do_action should be switched to an apply_filters even though, in this case, nothing will be done with the returned value.

[Howdy_McGee]

Action Hook switched to Filter Hook.

[johnbillion]

Notes:

• This hook is called as a filter five times and an action twice.
• ​Its developer reference page documents it as an action.
• ​There are very few plugins that actually hook into this filter/action, although quite a few that call the hook either as an action or a filter (having mostly copied and pasted from core by the looks of things).
• I also think this should be converted to always be a filter. Converting it to always be an action will break existing filters. I'd like a second opinion though.
• The patch needs to be updated to account for both places in core where this is called as an action:
  • ​https://github.com/WordPress/wordpress-develop/blob/f71140438beeae7c251464dbd65946fdab037c84/src/wp-admin/includes/class-custom-background.php#L568
  • ​https://github.com/WordPress/wordpress-develop/blob/f71140438beeae7c251464dbd65946fdab037c84/src/wp-admin/includes/class-custom-image-header.php#L885

[SergeyBiryukov]

Replying to johnbillion:

I also think this should be converted to always be a filter. Converting it to always be an action will break existing filters. I'd like a second opinion though.

That makes sense to me too.

Introduced in [6551] / #5418, setting the version accordingly.

[mhshujon]

If we change the existing action hook to a filter hook as like this https://core.trac.wordpress.org/attachment/ticket/57775/57775.diff , then what's the point of using filter hooks if we don't use the modified $file variable?