tests/test-issue660.t

grep: extract main search loop as searcher method

Still displayer part is in commands.grep(), the core grep logic is now
reusable. I'll revisit the displayer stuff later since it will be another
long series.

https://bz.mercurial-scm.org/660 and:
https://bz.mercurial-scm.org/322

  $ hg init
  $ echo a > a
  $ mkdir b
  $ echo b > b/b
  $ hg commit -A -m "a is file, b is dir"
  adding a
  adding b/b

File replaced with directory:

  $ rm a
  $ mkdir a
  $ echo a > a/a

Should fail - would corrupt dirstate:

  $ hg add a/a
  abort: file 'a' in dirstate clashes with 'a/a'
  [255]

Removing shadow:

  $ hg rm --after a

Should succeed - shadow removed:

  $ hg add a/a

Directory replaced with file:

  $ rm -r b
  $ echo b > b

Should fail - would corrupt dirstate:

  $ hg add b
  abort: directory 'b' already in dirstate
  [255]

Removing shadow:

  $ hg rm --after b/b

Should succeed - shadow removed:

  $ hg add b

Look what we got:

  $ hg st
  A a/a
  A b
  R a
  R b/b

Revert reintroducing shadow - should fail:

  $ rm -r a b
  $ hg revert b/b
  abort: file 'b' in dirstate clashes with 'b/b'
  [255]

Revert all - should succeed:

  $ hg revert --all
  forgetting a/a
  forgetting b
  undeleting a
  undeleting b/b

  $ hg st

Issue3423:

  $ hg forget a
  $ echo zed > a
  $ hg revert a
  $ hg st
  ? a.orig
  $ rm a.orig

addremove:

  $ rm -r a b
  $ mkdir a
  $ echo a > a/a
  $ echo b > b

  $ hg addremove -s 0
  removing a
  adding a/a
  adding b
  removing b/b

  $ hg st
  A a/a
  A b
  R a
  R b/b

commit:

  $ hg ci -A -m "a is dir, b is file"
  $ hg st --all
  C a/a
  C b

Long directory replaced with file:

  $ mkdir d
  $ mkdir d/d
  $ echo d > d/d/d
  $ hg commit -A -m "d is long directory"
  adding d/d/d

  $ rm -r d
  $ echo d > d

Should fail - would corrupt dirstate:

  $ hg add d
  abort: directory 'd' already in dirstate
  [255]

Removing shadow:

  $ hg rm --after d/d/d

Should succeed - shadow removed:

  $ hg add d
  $ hg ci -md

Update should work at least with clean working directory:

  $ rm -r a b d
  $ hg up -r 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg st --all
  C a
  C b/b

  $ rm -r a b
  $ hg up -r 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg st --all
  C a/a
  C b