HomePhabricator

mergestate: extract overridable methods for making/restoring file backups

Authored by martinvonz.

Description

mergestate: extract overridable methods for making/restoring file backups

In-memory merge currently still uses on-disk mergestate. That's mostly
harmless (I don't think I've seen any problem it's actually
caused). It's still a little weird. I'm planning to add an in-memory
mergestate, which will be used with overlayworkingctx. This patch
prepares for that by extracting that logic, so it's easier to change
per subclass.

Differential Revision: https://phab.mercurial-scm.org/D9038