tests/test-remotefilelog-bundles.t

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.

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ hg commit -qAm x
  $ echo y >> x
  $ hg commit -qAm y
  $ echo z >> x
  $ hg commit -qAm z

  $ cd ..

  $ hgcloneshallow ssh://user@dummy/master shallow -q
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
  $ cd shallow

Unbundling a shallow bundle

  $ hg strip -r 66ee28d0328c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg (glob)
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
  $ hg unbundle .hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 0 changes to 0 files
  new changesets 66ee28d0328c:16db62c5946f
  (run 'hg update' to get a working copy)

Unbundling a full bundle

  $ hg -R ../master bundle -r 66ee28d0328c:: --base "66ee28d0328c^" ../fullbundle.hg
  2 changesets found
  $ hg strip -r 66ee28d0328c
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg (glob)
  $ hg unbundle ../fullbundle.hg
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets 66ee28d0328c:16db62c5946f (2 drafts)
  (run 'hg update' to get a working copy)

Pulling from a shallow bundle

  $ hg strip -r 66ee28d0328c
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg (glob)
  $ hg pull -r 66ee28d0328c .hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg
  pulling from .hg/strip-backup/66ee28d0328c-3d7aafd1-backup.hg
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets 66ee28d0328c (1 drafts)
  (run 'hg update' to get a working copy)

Pulling from a full bundle

  $ hg strip -r 66ee28d0328c
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/66ee28d0328c-b6ee89e7-backup.hg (glob)
  $ hg pull -r 66ee28d0328c ../fullbundle.hg
  pulling from ../fullbundle.hg
  searching for changes
  abort: cannot pull from full bundles
  (use `hg unbundle` instead)
  [255]