tests/test-merge4.t

match: drop unnecessary removal of '.' from excluded roots

The repo root is nothing special when it comes to what directories to
visit: patterns like '-X relglob:*.py' should not exclude the top
directory, while '-X path:.' should (pointless as such a pattern may
be). The explicit removal of '.' from the set of excluded roots was
probably there to avoid removing the the root directory when any
patterns had been given, but since 20ad936ac5d2 (treemanifest: visit
directory 'foo' when given e.g. '-X foo/ba?', 2015-05-27), we only
exclude directories that should be completely excluded, so we no
longer need to special-case the root directory.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ rm b
  $ echo This is file c22 > c

Test hg behaves when committing with a missing file added by a merge

  $ hg commit -m "commit #3"
  abort: cannot commit merge with missing files
  [255]