tests: use "perf" as a the extension name in test-contrib-perf.t This is simpler and seems more "inline" with the name people usually use for this extensions.

shelve: do not update when keeping changes, just move the dirstate This is to leave the working directory unchanged. We reuse the match object as an optimisation.

shelve: refactor _shelvecreatedcommit's match object into calling site We might need to use this match object again to move the dirstate in case the user requested to `--keep` the changes.

shelve: new keep option Does nothing yet. The docstring describes what it will soon be doing.

diff: support diffing explicit files in subrepos Most other commands support implied recursion based on file names already.

fix: make the order of the work queue deterministic This makes any output generated during the parallel phase of execution stable if parallelism is disabled. This helps write tests like that in the future. Differential Revision: https://phab.mercurial-scm.org/D6166

fix: allow fixing untracked files when given as arguments It's more useful to fix the file than to silently avoid it when the user does this: hg fix --working-dir untracked-file We will still do nothing to ignored files, even if they are specified. This may be safer, given that such files can unexpectedly slip into the arguments via a shell glob or fileset. Differential Revision: https://phab.mercurial-scm.org/D6165

branchcache: have a hasnode function to validate nodes Upcoming patches will delay node validation until it's required. So we need to a way in branchcache class to check whether a node exists or node. Other options were making repo or changelog an attribute of branchcache object. But the branchcache depends on filters so I decided to pass a function object. Differential Revision: https://phab.mercurial-scm.org/D6157

branchcache: add attributes to track which nodes are verified Half of the cost of loading branchcache comes from verifiying all the nodes it has. We don't need to verify all the nodes in all the cases. Sometimes we need to verify only a set of nodes for a set of branches. We can ignore nodes of other branches as we are not going to read them. This patch introduces two attributes to branchcache class. _verifiedbranches is a set which will tell the branches for which it's head nodes are verified. _closedverified is a boolean which will tell whether all closednodes are verified or not. Another idea which I had was to keep a set of nodes which are verified, but it will be more ugly and difficult to track things on node level. Differential Revision: https://phab.mercurial-scm.org/D6156

branchcache: make entries a private attribute Differential Revision: https://phab.mercurial-scm.org/D6155