Lock Reindexing Allows Issue Transition

Problem

As per the documentation and in previous JIRA version, the instance should not be usable while lock reindexing is running. However, in JIRA 7.4.3, I was able to access the instance and transition an issue while performing lock reindexing.

Steps to Reproduce

1. Login as an admin and go to Administration > System > Indexing
2. Choose Lock JIRA and rebuild index
3. On another tab, login as another user
4. Go to one of the issues and transition it

Expected Behaviour

Users should not be able to access the instance

Actual Behaviour

Users can login and transition issues

Access Logs

0:0:0:0:0:0:0:1 1380x1164x1 admin [11/Sep/2017:23:01:16 +0800] "GET /jira_743/secure/WorkflowUIDispatcher.jspa?id=10300&action=11&atl_token=B2ZH-39NA-1BZH-ZON8|b97be39554bbeb92427f5fddbfe6ff9202088d3d|lin&decorator=dialog&inline=true&_=1505142044562 HTTP/1.1" 200 86 31353 "http://localhost:8743/jira_743/browse/BUS-1" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36" "1jm5vzn"