test-ancestor: move naive missing ancestor algorithm into a class This mirrors the change to the real missing ancestor algorithm in a previous patch.

ancestor.missingancestors: turn into a state-keeping class This allows multiple efficient missing ancestor queries against the same set of bases. In upcoming patches we'll also define ways to grow the set of bases. The fact that the test output hasn't changed establishes this patch's correctness.

ancestor.missingancestors: calculate start point after filtering revsvisit Any revs that are filtered out are also in basesvisit, which means they wouldn't be returned in the missing list anyway. There's no need to explore such revs or their ancestors. The 'if not revsvisit' check moves down because we can't call max() on an empty set.

ancestor.missingancestors: don't discard from basesvisit We only actually care about whether revsvisit is empty, so we can let basesvisit grow to arbitrary size. It turns out that this actually helps performance. For a large repo with hundreds of thousands of commits, hg perfrevset 'only(0, tip)' (basically the worst case, involving a full DAG traversal) goes from 1.63 seconds to 1.50. hg perfrevset 'only(tip, 0)' remains unchanged at 1.98 seconds.

test-ancestor: use random testing for missing ancestors We're going to make changes to the missing ancestor algorithm, and random testing will give us much more confidence than a fixed set of tests.

test-ancestor: define a main function We're going to add to it in upcoming patches.

test-ancestor: test iteration for lazyancestors This has some test coverage in test-revlog-ancestry.py, but not very much.

ancestor.lazyancestors: take parentrevs function rather than changelog Principle of least privilege, and it also brings this in line with missingancestors.

remove: avoid a bogus warning about no tracked files when removing '.' Previously, any files relative to the root of the repo that match the -I patterns would be deleted, but the command exited with 1 after printing a warning: $ hg remove -S -I 're:.*.txt' . removing sub1/sub2/folder/test.txt removing sub1/sub2/test.txt not removing .: no tracked files

remove: support remove with explicit paths in subrepos