perf: add a command to measure merge.calculateupdates perf The performance of merge.manifestmerge will be improved in upcoming patches. This command will be used to demonstrate the improvement.

hgk: fix a pyflakes error

dirstate.walk: fast path none-seen + match-always case for step 3 This case is a common one -- e.g. `hg diff`. For a repository with 170,000 files, this speeds up perfstatus from 0.95 seconds to 0.88.

dirstate.walk: fast path match-always case during traversal This case is a common one -- e.g. `hg status`. For a repository with 170,000 files, this speeds up perfstatus --unknown from 2.15 seconds to 2.09.

largefiles: fix _always for match overrides Upcoming patches will speed dirstate.walk up by not filtering based on the match function when match.always() is True. For that to work, match.always() needs to be accurate. Previously it wasn't so for largefiles.

dirstate.walk: remove subrepo and .hg from results before step 3 An upcoming patch will speed dirstate.walk up by not querying the results dict when it is empty. This ensures it is in some common cases. This should be safe because subrepos and .hg aren't part of the dirstate.

merge with stable

blackbox: account for another source of errors

hgk: remove regsub, split on \r instead No need to regsub all \r\n's to \n's, we can just split on \r as well; this may produce extra empty elements in the list, but they won't match anyway.

hgk: simplify tags parser As when hg tags is being called without -v option, it returns lines with two elements in each, we can just interate them as if it were a usual Tcl list using foreach and two variables. Line endings and whitespace don't matter when doing so, so we may keep them as is. When we're processing the lines, tag variable is assigned a tag name, and rev is a string in form of revision:hash which we can split on colon. As Tcl8.4 lacks lassign command, and using lindex makes code a bit less readable, we use foreach to iterate over two-element list.