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.
# Files that just need to be migrated to the formatter.
# Do not add new files here!
mercurial/cext/dirs.c
mercurial/cext/manifest.c
mercurial/cext/osutil.c
# Vendored code that we should never format:
contrib/python-zstandard/c-ext/bufferutil.c
contrib/python-zstandard/c-ext/compressionchunker.c
contrib/python-zstandard/c-ext/compressiondict.c
contrib/python-zstandard/c-ext/compressionparams.c
contrib/python-zstandard/c-ext/compressionreader.c
contrib/python-zstandard/c-ext/compressionwriter.c
contrib/python-zstandard/c-ext/compressobj.c
contrib/python-zstandard/c-ext/compressor.c
contrib/python-zstandard/c-ext/compressoriterator.c
contrib/python-zstandard/c-ext/constants.c
contrib/python-zstandard/c-ext/decompressionreader.c
contrib/python-zstandard/c-ext/decompressionwriter.c
contrib/python-zstandard/c-ext/decompressobj.c
contrib/python-zstandard/c-ext/decompressor.c
contrib/python-zstandard/c-ext/decompressoriterator.c
contrib/python-zstandard/c-ext/frameparams.c
contrib/python-zstandard/c-ext/python-zstandard.h
contrib/python-zstandard/zstd.c
contrib/python-zstandard/zstd/common/bitstream.h
contrib/python-zstandard/zstd/common/compiler.h
contrib/python-zstandard/zstd/common/cpu.h
contrib/python-zstandard/zstd/common/debug.c
contrib/python-zstandard/zstd/common/debug.h
contrib/python-zstandard/zstd/common/entropy_common.c
contrib/python-zstandard/zstd/common/error_private.c
contrib/python-zstandard/zstd/common/error_private.h
contrib/python-zstandard/zstd/common/fse_decompress.c
contrib/python-zstandard/zstd/common/fse.h
contrib/python-zstandard/zstd/common/huf.h
contrib/python-zstandard/zstd/common/mem.h
contrib/python-zstandard/zstd/common/pool.c
contrib/python-zstandard/zstd/common/pool.h
contrib/python-zstandard/zstd/common/threading.c
contrib/python-zstandard/zstd/common/threading.h
contrib/python-zstandard/zstd/common/xxhash.c
contrib/python-zstandard/zstd/common/xxhash.h
contrib/python-zstandard/zstd/common/zstd_common.c
contrib/python-zstandard/zstd/common/zstd_errors.h
contrib/python-zstandard/zstd/common/zstd_internal.h
contrib/python-zstandard/zstd/compress/fse_compress.c
contrib/python-zstandard/zstd/compress/hist.c
contrib/python-zstandard/zstd/compress/hist.h
contrib/python-zstandard/zstd/compress/huf_compress.c
contrib/python-zstandard/zstd/compress/zstd_compress.c
contrib/python-zstandard/zstd/compress/zstd_compress_internal.h
contrib/python-zstandard/zstd/compress/zstd_double_fast.c
contrib/python-zstandard/zstd/compress/zstd_double_fast.h
contrib/python-zstandard/zstd/compress/zstd_fast.c
contrib/python-zstandard/zstd/compress/zstd_fast.h
contrib/python-zstandard/zstd/compress/zstd_lazy.c
contrib/python-zstandard/zstd/compress/zstd_lazy.h
contrib/python-zstandard/zstd/compress/zstd_ldm.c
contrib/python-zstandard/zstd/compress/zstd_ldm.h
contrib/python-zstandard/zstd/compress/zstdmt_compress.c
contrib/python-zstandard/zstd/compress/zstdmt_compress.h
contrib/python-zstandard/zstd/compress/zstd_opt.c
contrib/python-zstandard/zstd/compress/zstd_opt.h
contrib/python-zstandard/zstd/decompress/huf_decompress.c
contrib/python-zstandard/zstd/decompress/zstd_decompress.c
contrib/python-zstandard/zstd/deprecated/zbuff_common.c
contrib/python-zstandard/zstd/deprecated/zbuff_compress.c
contrib/python-zstandard/zstd/deprecated/zbuff_decompress.c
contrib/python-zstandard/zstd/deprecated/zbuff.h
contrib/python-zstandard/zstd/dictBuilder/cover.c
contrib/python-zstandard/zstd/dictBuilder/cover.h
contrib/python-zstandard/zstd/dictBuilder/divsufsort.c
contrib/python-zstandard/zstd/dictBuilder/divsufsort.h
contrib/python-zstandard/zstd/dictBuilder/fastcover.c
contrib/python-zstandard/zstd/dictBuilder/zdict.c
contrib/python-zstandard/zstd/dictBuilder/zdict.h
contrib/python-zstandard/zstd/zstd.h
hgext/fsmonitor/pywatchman/bser.c
mercurial/thirdparty/xdiff/xdiff.h
mercurial/thirdparty/xdiff/xdiffi.c
mercurial/thirdparty/xdiff/xdiffi.h
mercurial/thirdparty/xdiff/xemit.c
mercurial/thirdparty/xdiff/xemit.h
mercurial/thirdparty/xdiff/xhistogram.c
mercurial/thirdparty/xdiff/xinclude.h
mercurial/thirdparty/xdiff/xmacros.h
mercurial/thirdparty/xdiff/xmerge.c
mercurial/thirdparty/xdiff/xpatience.c
mercurial/thirdparty/xdiff/xprepare.c
mercurial/thirdparty/xdiff/xprepare.h
mercurial/thirdparty/xdiff/xtypes.h
mercurial/thirdparty/xdiff/xutils.c
mercurial/thirdparty/xdiff/xutils.h
mercurial/thirdparty/zope/interface/_zope_interface_coptimizations.c