Martin von Zweigbergk <martinvonz@google.com> [Tue, 31 Jan 2017 12:32:45 -0800] rev 1786
uncommit: don't lose copy information of remaining files (issue5403)
As reported in the issue, "hg uncommit" would lose copy information of
the files that remained in the commit. The problem was simply that the
a dict of copies was iterated as "src, dst in copies.items()" where it
should have been "dst, src ...".