Martin von Zweigbergk <martinvonz@google.com> [Wed, 16 Jan 2019 17:33:47 -0800] rev 41384
localrepo: use context manager for transaction in commit()
A side-effect is that the transaction is released a little earlier, so
the "commit message saved in ..." messages now comes after the
"rollback completed" message. That seems slightly better to me.
Differential Revision: https://phab.mercurial-scm.org/D5622