tests/test-empty.t

graphlog: paths/-I/-X handling requires a new revset

The filtering logic of match objects cannot be reproduced with the existing
revsets as it operates at changeset files level. A changeset touching "a" and
"b" is matched by "-I a -X b" but not by "file(a) and not file(b)".

To solve this, a new internal "_matchfiles(...)" revset is introduced. It works
like "file(x)" but accepts more than one argument and its arguments are
prefixed with "p:", "i:" and "x:" to be used as patterns, include patterns or
exclude patterns respectively.

The _matchfiles revset is kept private for now:
- There are probably smarter ways to pass the arguments in a user-friendly way
- A "rev:" argument is likely appear at some point to emulate log command
  behaviour with regard to filesets: they are evaluated for the parent revision
  and applied everywhere instead of being reevaluated for each revision.

Create an empty repo:

  $ hg init a
  $ cd a

Try some commands:

  $ hg log
  $ hg grep wah
  [1]
  $ hg manifest
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions

Check the basic files created:

  $ ls .hg
  00changelog.i
  requires
  store

Should be empty:

  $ ls .hg/store

Poke at a clone:

  $ cd ..
  $ hg clone a b
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions
  $ ls .hg
  00changelog.i
  branch
  dirstate
  hgrc
  requires
  store

Should be empty:

  $ ls .hg/store