commit: show active bookmark in commit editor helper text If there is an active bookmark while committing, the bookmark name will be visible inside the commit message helper, below the branch name. This should make easier for the user to detect a mistaken commit parent, while working for example with a bookmark centric workflow like topic branches. The active bookmark is checked to be in the working directory, as pointed by Kevin Bullock, because otherwise committing would not advance it. In other words, this would not show the active bookmark name if the user changed the working tree parents with 'hg debugsetparents', for example.