Infinite loop in clean_dirsize_cache()

[raubvogel]

Since WP 5.6 there exsists

<?php
function clean_dirsize_cache( $path ){}

at functions.php:7725.
There we have

<?php
        while ( DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path ) {
                $path = dirname( $path );
                unset( $directory_cache[ $path ] );
        }

at functions.php:7735 which loops „forever“ if $path is something like c:\dir\subdir on Windows.

<?php
$path = dirname( $path );

returns the parent path in each step and gets „stuck“ at c:\.

[raubvogel]

Btw. this breaks the media upload in my WordPress because media upload calls clean_dirsize_cache().

[audrasjb]

As per today's 5.6.1 bug scrub, moving this ticket to Future release pending further informations/context on the issue/bug (and a patch/unit tests).

[raubvogel]

Debug Screenshot 1

[raubvogel]

Debug Screenshot 1

[raubvogel]

Debug Screenshot 3

[ocean90]

#52292 was marked as a duplicate.

[codezen8]

Is there a schedule for this patch? I can confirm that media uploads are broken in WordPress 5.6.x for multi-site running on a Windows server. I have tested the patch above and can also confirm that with that line in place media uploads work as expected.

[sjlevy]

To comment also in support of this patch: it appears to work fine and needed to be re-applied after the last WP update.

I encountered the infinite loop issue on 3 of my windows server-based multisites a couple of months ago-- located the offending line of code, and then subsequently found this ticket. Thank you

[drosmog]

Bug continues to affect IIS in WordPress 5.7. Line changed to 7813 in functions.php.

[teachlynx]

Same as @drosmog, bug continues to affect IIS 10 in WordPress 5.7. Line changed to 7813 in functions.php.

[EkoJr]

May not be the most elegant solution, but it is a small simple change, and I'm a little surprised this ticket wouldn't have a high priority & got postponed to a future subversion considering it affects IIS servers and would appear to be a blocker bug for media.

Basically, the modified code compares the $last_path with the current $path, and if the $path is the same as it previously was in the previous iteration, it will then break out of the loop.

Original Code (WP 5.7)
wp-includes/functions.php:7812 > function clean_dirsize_cache( $path )

<?php
while ( DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path ) {
        $path = dirname( $path );
        unset( $directory_cache[ $path ] );
}

Modified Code

<?php
$last_path = '';
while ( DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path && $last_path !== $path ) {
        $last_path = $path;
        $path      = dirname( $path );
        unset( $directory_cache[ $path ] );
}

It's more of a conceptual solution, and someone may have a better answer. So, I am a bit hesitant creating a commit for this (plus, it's been awhile since I touched SVN).