WP_Upgrader goes too far up when enumerating parent paths on a network share

[vfs_hobbes]

In /wp-admin/includes/class-wp-upgrader.php:

When is_vcs_checkout() is walking up parent folders, the behavior of dirname() causes WordPress to check for folders that couldn't possibly exist. For example, if "inetpub-share" was the name of a share on machine "myserver", the following folders might be searched for source control folders:

• \\myserver\inetpub-share\wwwroot\.git
• \\myserver\inetpub-share\.git
• \\myserver\.git
• \.git

Note that the last two are not even subfolders of "inetpub-share". That is, the search should stop at "\\myserver\inetpub-share\.git" because "inetpub-share" should be considered a top-level folder.

Even more concerning is that checking for "\\myserver\.git" and "\.git" are very expensive operations in a network environment, which means that the upgrade logic takes a very long time or will time out.

My proposed remedy is to change this line:

if ( $context_dir == dirname( $context_dir ) )

to

if ( $context_dir == dirname( $context_dir ) 
    || (substr($context_dir , 0, 2)=='\\\\' && strpos(dirname( $context_dir ), '\\', 2)===false)

Thoughts?

[dd32]

As a temporary workaround, you could map the Network Share to a Drive Letter (which is what most people do AFAIK) and serve off of that.

[vfs_hobbes]

Replying to dd32:

As a temporary workaround, you could map the Network Share to a Drive Letter (which is what most people do AFAIK) and serve off of that.

I would consider that as a last resort because I am running each site under its own credentials (for security purposes), which means that [each user would need its own mapped drive](​https://support.microsoft.com/en-us/kb/257174), which in turn causes performance issues and maintenance issues.

Hobbes