contrib/fuzz/dirstate_corpus.py

convert: don't drop commits that are empty in the source when using --filemap

I ran into this when using `hg lfconvert --to-normal` (which uses the filemap
class internally), and saw that commits with nothing but a branch change were
dropped.  We could put in an option that only lfconvert uses internally.  But
silently dropping anything other than a commit where all changes were excluded
seems unintended.  For example, there's a message in mercurial_sink.putcommit()
if it drops an empty commit.  (And the reason that isn't kicking in here is
because lfconvert isn't passing --filemap, so the self.filemapmode conditional
there is always False.)

The naive change of `return not files` broke test-convert-filemap.t, so this is
a little more elaborate than needed for converting from largefiles.

from __future__ import absolute_import, print_function

import argparse
import os
import zipfile

ap = argparse.ArgumentParser()
ap.add_argument("out", metavar="some.zip", type=str, nargs=1)
args = ap.parse_args()

reporoot = os.path.normpath(os.path.join(os.path.dirname(__file__),
                                         '..', '..'))
dirstate = os.path.join(reporoot, '.hg', 'dirstate')

with zipfile.ZipFile(args.out[0], "w", zipfile.ZIP_STORED) as zf:
    if os.path.exists(dirstate):
        with open(dirstate) as f:
            zf.writestr("dirstate", f.read())