convert_git: avoid returning two entries for the same file in getchanges
This could happen in merge changesets if the merged file was different
from both parents.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init a
cd a
echo a > a
hg ci -Ama
hg qnew a.patch
echo a >> a
hg qrefresh
hg qnew b.patch
echo b > b
hg add b
hg qrefresh
hg qnew c.patch
echo c > c
hg add c
hg qrefresh
hg qgoto a.patch
hg qgoto c.patch
hg qgoto b.patch