view tests/test-issue619.t @ 33003:f63d111258da

revset: add startdepth limit to ancestors() as internal option

This is necessary to implement the set{gen} (set subscript) operator. For
example, set{-n} will be translated to ancestors(set, depth=n, startdepth=n).

https://www.mercurial-scm.org/wiki/RevsetOperatorPlan#ideas_from_mpm

The UI is undecided and I doubt if the startdepth option would be actually
useful, so the option is hidden for now. 'depth' could be extended to take
min:max range, in which case, integer depth should select a single generation.

  ancestors(set, depth=:y)  # scan up to y-th generation
  ancestors(set, depth=x:)  # skip until (x-1)-th generation
  ancestors(set, depth=x)   # select only x-th generation

Any ideas are welcomed.

  # reverse(ancestors(tip)) using hg repo
  3) 0.075951
  4) 0.076175

https://bz.mercurial-scm.org/619

  $ hg init
  $ echo a > a
  $ hg ci -Ama
  adding a

  $ echo b > b
  $ hg branch b
  marked working directory as branch b
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -Amb
  adding b

  $ hg co -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

Fast-forward:

  $ hg merge b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -Ammerge

Bogus fast-forward should fail:

  $ hg merge b
  abort: merging with a working directory ancestor has no effect
  [255]

Even with strange revset (issue4465)

  $ hg merge ::.
  abort: merging with a working directory ancestor has no effect
  [255]