tests: don't use dates before epoch in test-keyword.t
Timezone offsets of less than a minute is not shown but can cause displayed
dates to be before epoch start - and dates before epoch start is not shown
correctly on Windows (see also 4d5b12a5517b).
These 'negative' dates could be considered undefined behaviour so we don't care
and swap the tests values for timestamp and timezone.
[ original upstream message ]
strip: incrementally update the branchheads cache after a strip
This function augments strip to incrementally update the branchheads cache
rather than recompute it from scratch. This speeds up the performance of strip
and rebase on repos with long history. The performance optimization only
happens if the revisions stripped are all on the same branch and the parents of
the stripped revisions are also on that same branch.
This adds a few test cases, particularly one that reproduces the extra heads
that mpm observed.
[ original upstream message ]