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.
adding foo
Patch queue now empty
applying patch1
applying patch2
applying bad-patch
transaction abort!
rollback completed
cleaning up working directory...done
abort: decoding near 'é': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)!
changeset: 0:bbd179dfa0a7
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
% bar should be gone; other unknown/ignored files should still be around
? untracked-file
I .hgignore
C foo