Media files cannot be deleted under Windows since 5.2

[tonybogdanov]

The wp_delete_file_from_directory function was introduced in 4.9.7 and is used when deleting media files from the uploads directory. However, it's internals were changed in 5.2 and the function no longer works on Windows.

The actual deletion is omitted if this check is truthy:

https://core.trac.wordpress.org/browser/tags/5.2/src/wp-includes/functions.php#L6292

And on a Windows machine trailingslashit adds a forward slash / at the end of the path whereas the first part of the path is using backslashes (due to realpath), thus strpos fails.

Additionally returning FALSE from wp_delete_attachment_files doesn't seem to be accounted for (haven't dug into it). When I delete a file in the media panel it "succeeds" even though the physical file hasn't been deleted.

[SergeyBiryukov]

Introduced in [45177].

[joemcgill]

Looks like this was just missed in testing. Short term would be to revert [45177] in the next minor unless someone has a patch to resolve this fully without reintroducing the issues from #44563 in the mean time.

[SergeyBiryukov]

The gist is that wp_normalize_path() needs to be applied both before and after realpath(), which may seem redundant at a glance, but was deemed necessary when testing the original [43392] changeset.

[SergeyBiryukov]

In 45352:

Media: Fix deletion of files on Windows.

wp_delete_file_from_directory() should always normalize file paths before comparing.

Props tonybogdanov, SergeyBiryukov.
Fixes #47185.

[SergeyBiryukov]

In 45353:

Media: Fix deletion of files on Windows.

wp_delete_file_from_directory() should always normalize file paths before comparing.

Props tonybogdanov, SergeyBiryukov.
Merges [45352] to the 5.2 branch.
Fixes #47185.