Key not re-used when move Jira issue back to a project

Question

I am using Jira 7.6.1 and I created an issue which got assigned key TEST-21 and then I moved it to another project so that it got key PROJ-364. After moving I can still access the issue as TEST-21 which is good. However I then moved the issue back to project TEST and rather than it reusing the existing TEST-21 key that still points to it, it was assigned a new key of TEST-22. So now I can access the issue via TEST-21, TEST-22 & PROJ-364.

Would it be possible to discover whether there is an existing key for the destination project that already points to the issue and reuse that rather than create another key?

Nic Brough -Adaptavist- · Answer

It doesn't matter - you moved it out of the project, therefore there's a hole.

unknown · Answer

I am talking about reusing an existing key that already points to the issue being moved. That is, create issue 12345 under TEST so we get TEST-21 => 12345. Then move it to PROJ so we get PROJ-364 => 12345. Then move it back to TEST and rather than get a new key TEST-22 pointing to 12345 we get the current TEST-21 that is already pointing to it.

Nic Brough -Adaptavist- · Answer

You could raise it, but Atlassian are never going to do it, as it's complex and not useful.

Holes in the issue key sequence are caused by users deleting or moving issues.  If an issue is moved, you don't want to re-use the key, because Jira knows where the issue has gone and gives that to people looking for the old key.  A new one would break that.  If the issue has been deleted, the hole in the sequence is the *only* indicator that it's been killed off, and again, it will confuse people who had any reference to it - to see a new issue with the number they expect that is probably totally irrelevant.