hgweb: fix incorrect way to count revisions in log (issue3977)
Actual amount of revisions is used now instead of their numbers in the repo
before to deal with skipped numbers correctly.
This iterates starting from the newest revision (which is shown on top)
yielding up to the specified count, instead of the reversed order used before.
Effect of this change on efficiency is negligible, when the same changesets are
returned.
$ hg init t
$ cd t
$ echo a > a
$ hg add a
$ hg commit -m test
$ rm .hg/requires
$ hg tip
abort: index 00changelog.i unknown format 2!
[255]
$ echo indoor-pool > .hg/requires
$ hg tip
abort: unknown repository format: requires features 'indoor-pool' (upgrade Mercurial)!
[255]
$ echo outdoor-pool >> .hg/requires
$ hg tip
abort: unknown repository format: requires features 'indoor-pool', 'outdoor-pool' (upgrade Mercurial)!
[255]
$ cd ..