These URLs kill me, I share a lot of links and these branches use full commit strings (instead of just "default" or "stable" human readable) and the links it creates to PRs includes the actual title (which I find I can delete manually, but this is the default behaviour).
This is good pattern but not implemented correctly. It should rewrite to full correct url. It can be abuse like this:
/140/_/ThisProjectSucksDontUseIt-UseThisOneXXXXXX
https://kallithea-scm.org/repos/kallithea/pull-request/140/_...