REST API saves attachments with absolute path for `_wp_attached_file` on Windows platforms

[redcastor]

On windows, create media with rest api insert the meta "_wp_attached_file" not correctly.
It save the absolute path and not the relative path.

the function "wp_slash" add backslash in windows file path.

file: class-rest-attachements-controller.php
line: 150

<?php
$id = wp_insert_post( wp_slash( (array) $attachment ), true );

[bobbingwide]

This bug causes a problem with Gutenberg. See ​https://github.com/WordPress/gutenberg/issues/5332

[ocean90]

~Looks like _wp_relative_upload_path() is missing here.~

[ocean90]

Attached 40861.patch​ and 40861.2.patch​.

Since wp_insert_post() expects slashed data we should unslash the file argument as well, done in 40861.patch​.

In 40861.2.patch​ I switched to wp_insert_attachment() so the file argument doesn't get slashed in the first place.

[bobbingwide]

The second patch makes it a lot more obvious that it's difficult to use the REST API to create an attachment which is actually attached to something! Is that one of the reasons for the 'rest_insert_attachment' action hook?

[ocean90]

Replying to bobbingwide:

The second patch makes it a lot more obvious that it's difficult to use the REST API to create an attachment which is actually attached to something!

Not sure I'm following. wp_insert_attachment() is a simple wrapper for wp_insert_post() without any additional filters. What's the issue you're seeing here?

[danielbachhuber]

Let's land this in 4.9.7 so we can see this sooner rather than later.

[ocean90]

4.9.7 has been released, moving to next milestone.

[SergeyBiryukov]

In 43529:

REST API: Ensure attachments created with WP_REST_Attachments_Controller::create_item() on Windows have a relative path.

Props ocean90, SergeyBiryukov, redcastor.
Fixes #40861.

[SergeyBiryukov]

In 43530:

REST API: Ensure attachments created with WP_REST_Attachments_Controller::create_item() on Windows have a relative path.

Props ocean90, SergeyBiryukov, redcastor.
Merges [43529] to the 4.9 branch.
Fixes #40861.