I'm using Mercurial with TortoiseHG Workbench. I closed a branch by accident. I tried updating to it and making a commit to see if it would reopen (since there didn't appear to be an option to reopen the branch)
I was able to make a commit and push, but on TortoiseHG, it still says that the Head is Closed!
Option to reopen branch doesn't exist, because commit on top of closed head effectively open this head (and commited head must not be "closed": it's metadata from previous changeset): test this with hg branches
and|or hg heads
Additional reading: