tests/test-merge-subrepos.t

commandserver: drop tell() and seek() from channels (issue5049)

These operations are obviously invalid for file-like channels because they
will read or write protocol headers.

This patch works around the issue that "hg archive" generates a corrupted
zip file on Windows commandserver because of unusable tell() implementation.
But the problem still occurs without using a commandserver.

  $ hg archive -R not-small-repo -t zip - | cat > invalid.zip

So, this patch cannot fix the issue5049 completely.

  $ hg init

  $ echo a > a
  $ hg ci -qAm 'add a'

  $ hg init subrepo
  $ echo 'subrepo = http://example.net/libfoo' > .hgsub
  $ hg ci -qAm 'added subrepo'

  $ hg up -qC 0
  $ echo ax > a
  $ hg ci -m 'changed a'
  created new head

  $ hg up -qC 1
  $ cd subrepo
  $ echo b > b
  $ hg add b
  $ cd ..

Should fail, since there are added files to subrepo:

  $ hg merge
  abort: uncommitted changes in subrepository 'subrepo'
  [255]