[PATCH 0 of 1 STABLE] revset: evaluate sub expressions correctly (issue3775)

[FUJIWARA Katsunori]

This patch series fixes issue3775.

BTW, some revset implementations use "list(repo)" as "entire revisions
in the repo", and it seems to be inefficient, because it causes
immediate creation of list object containing all revision numbers in
the repo.

IMHO, "repo.changelog" should be used instead of it.

But it also seems to have not so serious impact for average revset
expressions (not used repeatedly in the loop, for example). So I'm
planing to send the patch to fix it after current code freeze.

Or should I send it in this code freeze, too ?