PHP Notice in WP Site Query

[spacedmonkey]

While running multisite in PHP 7.3, I get the following notice error.

`Notice: compact(): Undefined variable: groupby in /var/www/html/wordpress/wp-includes/class-wp-site-query.php on line 597`

This only appears on uncached site query calls, so it harder to notice.

[johnjamesjacoby]

Confirmed. PHP 7.3 complains about this now.

[spacedmonkey]

Updated the patch with another edge case.

[desrosj]

These were fixed in [43832] and merged into trunk in [44166]. There is one issue that needs to be fixed in get_site_ids().

$groupby is initialized too late and can incorrectly overwrite values. This was caused in [44166].

[desrosj]

Move $groupby higher up to the correct location.

[spacedmonkey]

@desrosj 45582.3.diff changes seem fine to me.

[desrosj]

In 44186:

Networks and Sites: Fix incorrect variable location.

This fixes an issue introduced in [44166] where the $groupby variable was inserted too low in the get_site_ids() function while merging [43832] into trunk. The merged location did not account for a new conditional statement that existed only in trunk, and would have resulted in values assigned to $groupby being erased in certain scenarios.

Props spacedmonkey.

See #44416.
Fixes #45582.

[spacedmonkey]

@desrosj This change needs to be backdated all the way to 4.6, if possible.

[spacedmonkey]

@desrosj Why was this bumped to 5.1? This is a bug.

[SergeyBiryukov]

Replying to spacedmonkey:

Why was this bumped to 5.1? This is a bug.

The issue only exists in trunk due to the code added in [43010], where $groupby is defined inside a conditional block. The 5.0 branch does not have that code and should not have the issue.

[desrosj]

@SergeyBiryukov is correct. I should have closed this ticket as a duplicate of #44416 and fixed the issue there. New Sites API code only existed in trunk and the 5.0 branch code did not merge properly. [44186] will be a 5.1 change only.