repair: remove unnecessary locking for bookmarks The caller has already locked the repo.

repair: move check for existing transaction earlier Several benefits: * Gets close the comment describing it * Splits off unrelated comment about "backup" argument * Error checking is customarily done early * If we added an early return to the method, it would still consistently fail if there was an existing transaction (so we would find and fix that case quickly) One test needs updating with for this change, because we no longer create the backup bundle before we fail. I don't see much reason to create that backup bundle. If some command was adding content and then trying to strip it as well within the transaction, we would have a backup for the user, but the risk of that not being discovered in development seems very small.

strip: remove unncessary "del" and inline variable

repair: clarify in comment that caller must take lock, but not transaction I have checked that all callers have already taken the lock (and if they hadn't, we should have seen tests fail thanks to the 'transaction requires locking' devel warning in localrepo.transaction()).

amend: use context manager for locking

strip: use context manager for locking and transaction in stripcmd()

strip: use context manager for locking in strip()

rebase: use context manager for locking in pullrebase()

rebase: use context manager for locking in rebase()

test-http-proxy: redirect proxy stdout to /dev/null This output hasn't been getting flushed, but would alter the log if it ever grew large enough. See 23b07333a8b2.