Update error: not able to create directory

[afragen]

At some point in the past few week my updates broke. I am using 4.2-beta3-31921 and I'm reasonable certain this did work in beta2.

This comes about when updating using my ​GitHub Updater plugin. The actual updating is from core the plugin just make core aware of the update.

Currently the error I'm getting is that I am unable to create a directory.

Updating works on 4.1.1

[dd32]

Moving to 4.2 for investigation.

@afragen can you provide a direct link to a public plugin using the system for testing with? (latest version is fine)

[afragen]

​https://github.com/afragen/test-plugin is what I use.

I'm doing some more testing and sometimes I get the error but the plugin does update.

[dd32]

As I somewhat suspected, it's because it tries to create a folder called 0, whereas previously it tried to create one called 0.tmp, as the basename of the URL it's downloading is 0 (ie. the file is 0.7.3).

That changed in #30945.

What I suspect is happening, is something is calling empty() on the directory name (0), but i'm not sure where yet.

[afragen]

Previously, creating a folder 0.tmp worked just fine. It must have been the addition of the extension. Thanks for letting me know I'm not going crazy.

FWIW, I seem to recall it always created a 0.tmp folder no matter what the actual download.

[afragen]

I didn't have the issue in #30945 because my plugin has a renaming function to fix this.

[afragen]

I think I found a solution, but I'm not set up to create a diff. Starts line 266 in /wp-admin/includes/class-wp-upgrader.php

		// We need a working directory - Strip off any .tmp or .zip suffixes
		// If empty after stripping create 'temp' name
		$package_stripped = basename( basename( $package, '.tmp' ), '.zip' );
		if ( empty( $package_stripped ) ) {
			$package_stripped = 'temp';
		}
		
		$working_dir = $upgrade_folder . $package_stripped;

[dd32]

In 31936:

Add some logic into wp_tempnam to prevent it creating 'falsey' directory names that might get used elsewhere within WordPress.
Although this logic looks a little strange at this low level, it's the best location within the Upgrades code for it to happen.
Fixes #31811

[afragen]

Thanks @dd32. Looking forward to next nightly that has this fix.

[dd32]

In 32322:

When creating a temporary file treat the / directory properly, to prevent it ending up in an endless self-calling loop.
Props hnle, taka2. Fixes #32135. See #31811

[dd32]

In 32324:

When creating a temporary file treat the / directory properly, to prevent it ending up in an endless self-calling loop.
Props hnle, taka2. Fixes #32135. See #31811
Merges [32322] to the 4.2 branch.

[tellyworth]

There's an obscure regression here. The old regex would strip the extension and add '.tmp' in one preg_replace. The new version strips the extension first, then concats '.tmp' separately, regardless of whether or not there was an extension passed in.

So the previous version, if given a filename with no extension, would produce a temp name with no extension. Now the result always has a '.tmp' extension, regardless of the input.

It's arguably correct behaviour, just posting here because we found a plugin that was tripped up by the change.

[dd32]

#32121 was marked as a duplicate.