Steps to reproduce:

1. Navigate to a task with a lot of comments
2. Click "Show Older Changes" to do just that
3. Click the date to get the hash for one of the newly-shown comments into your address bar
4. Copy the task number and hash (e.g. on my test install, it was T1#74)
5. Paste that reference into the comment box (still on the same task) and submit it
6. The task will reload, again with the comments hidden
7. Click the link in the comment you just submitted

What happens:

• Nothing

What should happen:

• Old comments should automatically load so that the link can be followed to view the referenced comment. (This works if you paste the same reference into a comment in a different task, just not if you reference an earlier comment in the same task.)

I guess other applications with comments such as Differential may suffer from the same problem.

Version tested on:

phabricator 33f40e3e85b8c3241435b274c490d73c0017a520 (Thu, Jun 9)
arcanist 0249f90a9a4aa42da0823673a6ac8c620251d82a (Sat, May 21)
phutil 00c08511c862f2020efe96cce1b0c5a43491ac32 (Sat, Jun 4)

The phabricator version is 03403ca8b077015928d1b08afe929f9c45526edb with a couple of (unrelated) patches applied