context: generate filtered manifest efficiently for exact matchers When the matcher is exact, there's no reason to iterate over the entire manifest. It's much more efficient to iterate over the list of files instead. For a repository with approximately 300,000 files, this speeds up hg log -l10 --patch --follow for a frequently modified file from 16.5 seconds to 10.5 seconds.

manifestdict: add a new method to intersect with a set of files This is meant to be used when the set of files is known in advance, e.g. with a match object with no patterns.

log: use an exact matcher for --patch --follow The arguments to log --patch --follow are expected to be exact paths. This will be used to make manifest filtering for these cases more efficient in upcoming patches.

merge with stable

log: make --patch --follow work inside a subdirectory Previously, the 'patch' code for hg log --patch --follow would try to resolve patterns relative to the repository root rather than the current working directory. Fix that by using match.files instead of pats, as done elsewhere nearby.

mergetools: add --nofork option to gvimdiff.diffargs for extdiff Without --nofork, temporary files are removed immediately before gvimdiff starts. "-d -g -O" are put just for consistency with gvimdiff.args.