view tests/test-backwards-remove.t @ 20613:10433163bf57

revset: add 'only' revset

Adds a only() revset that has two forms:

only(<set>) is equivalent to "::<set> - ::(heads() - heads(<set>::))"

only(<include>,<exclude>) is equivalent to "::<include> - ::<exclude>"

On a large repo, this implementation can process/traverse 50,000 revs in 0.7
seconds, versus 4.2 seconds using "::<include> - ::<exclude>".

This is useful for performing histedits on your branch:
hg histedit -r 'first(only(.))'

Or lifting branch foo off of branch bar:
hg rebase -d @ -s 'only(foo, bar)'

Or a variety of other uses.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ ls
  a
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

B should disappear

  $ ls
  a