filemerge: when merge tool uses $output, don't leave markers in $local
As explained in the previous patch, we incorrectly leave conflict
markers in both `$local` and `$output` since D12190. I don't
understand why it broke but the fix is simple and clear after all the
recent refactoring.
Differential Revision: https://phab.mercurial-scm.org/D12379
from __future__ import absolute_import, print_function
import sys
for line in sys.stdin:
if line.lower() in ("message-id: \n", "in-reply-to: \n"):
line = line[:-2]
print(line, end="")