Web updater is broken in extension registration.

This way it works because CheckUser.php is not empty yet and doesent redirect o extension.json. Please see the one after this to find where problem happends.

steps to reproduce this step is

require_once ( "$IP/extensions/CheckUser/CheckUser.php" );

then go to mw-config on your website then go through step and click next on upgrade look through the log when the updater is finished there should be cu_ prefix meaning that the sql for checkuser was done.

This step is for extension.json to show difference.

steps to reproduce this step is

• Add wfLoadExtension( 'CheckUser' ); to LocalSettings.php

• Then once you have added it to LocalSettings.php go to mw-config

• Follow through steps and when you get the final stage when it upgrades click next.

• Once upgrade complete look through log for cu_ prefix in log if not found then there is problem with sql updater.

This is a problem with extension registration because if you use the old php file it works as long as it not redirected to extension.json/skin.json.

I am also having this problem with math at https://gerrit.wikimedia.org/r/#/c/187654/.

Please fix problem with web updater not working with extension registration.