localrepo: strip now incrementally updates the branchheads cache...
localrepo: strip now incrementally updates the branchheads cache
Destroying history via strip used to invalidate the branchheads cache,
causing it to be regenerated the next time it is read. This is
expensive in large repos. This change converts strip to pass info to
localrepo.destroyed() to enable to it to incrementally update the
cache, improving the performance of strip and other operations that
depend on it (e.g., rebase).
This change also strengthens a bit the integrity checking of the
branchheads cache when it is read, by rejecting the cache if it has
nodes in it that no longer exist.
