topic: make hg stack work for branches with double slashes in them Other commands are likely affected as well. Things to note: we're using FQBN-formatted branch instead of full branch//namespace/topic in the workingctx.dirty() check because otherwise, if you had no topic active and were trying to update to a topic, wdir would be considered to be dirty and update would abort (same with unset topic namespace and trying to update to a changeset with topic namespace set). With just a bare branch, this doesn't happen, because you can't deactivate a branch. This is caught by test-topic.t.