Steps to replicate the issue
- Navigate to https://patchdemo.wmcloud.org/.
- Under 'Start with version', select REL1_43.
- Under 'Then, apply patches', enter 1134228, and select the patch that comes up (https://gerrit.wikimedia.org/r/1134228).
- Click the 'Create demo' button.
What happens?
The wiki is successfully created, but the patch doesn't get applied.
The wiki-creation console output shows that Patch Demo is doing something to try to apply the patch:
Fetching and applying patches (1/1)... PATCHDEMO='/var/www/html' NAME='2f40feaf77' REPO='w/.' REF='refs/changes/28/1134228/1' BASE='origin/master' HASH='b06a1063087dd14e120317684630b7e9181d323b' \ /var/www/html/new/applypatch.sh + cd /var/www/html/wikis/2f40feaf77/w/. + git fetch origin refs/changes/28/1134228/1 From https://gerrit.wikimedia.org/r/mediawiki/core * branch refs/changes/28/1134228/1 -> FETCH_HEAD + : + git rev-list --cherry-pick --right-only HEAD...b06a1063087dd14e120317684630b7e9181d323b '^origin/master' --count + grep '^0$' 0
However, the patch doesn't actually seem to get applied -- https://gerrit.wikimedia.org/r/1134228 adds Special:Versions as an alias to Special:Version; but the created wiki doesn't recognize that alias.
What should have happened instead?:
The patch should have been applied to the wiki. If the patch can't be applied, IMO the wiki creation should fail.
Other information/Notes
One use case for this functionality (i.e., applying patches to release-branches) is being able to work out whether or not a given patch has caused a specific regression. E.g., for T396233, I suspected that it might have been caused by https://gerrit.wikimedia.org/r/1143497; and I was hoping to test this theory by (a) applying that patch to a demo-wiki running REL1_44, and (b) comparing the results to a REL1_44 wiki with no patches applied.