merge

bookmarks: moving the active bookmark deactivates it After this change, moving the active bookmark somewhere other than the current changeset (i.e., with --rev) deactivates it. Previously it would remain in .hg/bookmarks.current, which seems like a bug.

bookmarks: allow (re-)activating a bookmark on the current changeset Allow a bookmark that points to the current changeset to be made the active bookmark without requiring --force. Previously, this would've aborted with: abort: bookmark 'Z' already exists (use -f to force)

applyupdates: assign variable before we try to use it (issue3855) The variable 'fd' was getting used with a value left over from a prior iteration, causing a KeyError: '.hgsubstate'.

revset: don't abort when regex to tag() matches nothing (issue3850) This makes the tag("re:...") revset consistent with branch("re:...").

rebase: fix --collapse when a file was added then removed When a series of commits first adds a file and then removes it, hg rebase --collapse prompts whether to keep the file or delete it. This is due to it reusing the branch merge code. In a noninteractive terminal it defaults to keeping the file, which results in a collapsed commit that is has a file that should be deleted. This bug resulted in developers accidentally commiting unintentional changes to our repo twice today, so it's fairly important to get fixed. This change allows rebase --collapse to tell the merge code to accept the latest version every time without prompting. Adds a test as well.

Merge

grep: use re2 if possible Since re2 is enormously faster than Python's re module, this should help performance, ceteris paribus. grep currently has other huge performance problems that mask any gain :-(