branchmap: check node against changelog instead of repo...
branchmap: check node against changelog instead of repo
Testing 'node in repo' requires constructing a changectx, which is a little
expensive. Testing 'repo.changelog.hasnode(node)' is notably faster. This
saves 10-20ms off of every command, when testing a few thousand nodes from the
branch cache.
I considered changing the implementation of localrepository.__contains__ so
every place would benefit from the change, but since
localrepository.__contains__ uses changectx to check if the commit exists, it
means it supports a wider range of possible inputs (like revs, hashes, '.',
etc), so it seemed unnecessarily risky.
