Unencoded # in branch name (BB-7051)

I have a repository with a branch that contains a # character, i.e. hotfix-#434

If I click on the branches icon on the right to reveal the list of branches and click on the branch it takes me to a URL with the # character unencoded and I get a 404, i.e.

https://bitbucket.org/brightmachine/reponame/commits/branch/hotfix-#434

If I encode the hash in the URL to get this:

https://bitbucket.org/brightmachine/reponame/commits/branch/hotfix-%23434

… then I get the page I was looking for.