view tests/test-merge-closedheads.t @ 41247:a89b20a49c13

rust-cpython: using MissingAncestors from Python code

As precedently done with LazyAncestors on cpython.rs, we test for the
presence of the 'rustext' module.

incrementalmissingrevs() has two callers within the Mercurial core:
`setdiscovery.partialdiscovery` and the `only()` revset.

This move shows a significant discovery performance improvement
in cases where the baseline is slow: using perfdiscovery on the PyPy
repos, prepared with `contrib/discovery-helper <repo> 50 100`, we
get averaged medians of 403ms with the Rust version vs 742ms without
(about 45% better).

But there are still indications that performance can be worse in cases
the baseline is fast, possibly due to the conversion from Python to
Rust and back becoming the bottleneck. We could measure this on
mozilla-central in cases were the delta is just a few changesets.
This requires confirmation, but if that's the reason, then an
upcoming `partialdiscovery` fully in Rust should solve the problem.

Differential Revision: https://phab.mercurial-scm.org/D5551

  $ hgcommit() {
  >    hg commit -u user "$@"
  > }

  $ hg init clhead
  $ cd clhead

  $ touch foo && hg add && hgcommit -m 'foo'
  adding foo
  $ touch bar && hg add && hgcommit -m 'bar'
  adding bar
  $ touch baz && hg add && hgcommit -m 'baz'
  adding baz

  $ echo "flub" > foo
  $ hgcommit -m "flub"
  $ echo "nub" > foo
  $ hgcommit -m "nub"

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "c1" > c1
  $ hg add c1
  $ hgcommit -m "c1"
  created new head
  $ echo "c2" > c1
  $ hgcommit -m "c2"

  $ hg up -C 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo "d1" > d1
  $ hg add d1
  $ hgcommit -m "d1"
  created new head
  $ echo "d2" > d1
  $ hgcommit -m "d2"
  $ hg tag -l good

fail with three heads
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  abort: branch 'default' has 3 heads - please merge with an explicit rev
  (run 'hg heads .' to see heads)
  [255]

close one of the heads
  $ hg up -C 6
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hgcommit -m 'close this head' --close-branch

succeed with two open heads
  $ hg up -C good
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hgcommit -m 'merged heads'

hg update -C 8
  $ hg update -C 8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

hg branch some-branch
  $ hg branch some-branch
  marked working directory as branch some-branch
  (branches are permanent and global, did you want a bookmark?)
hg commit
  $ hgcommit -m 'started some-branch'
hg commit --close-branch
  $ hgcommit --close-branch -m 'closed some-branch'

hg update default
  $ hg update default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
hg merge some-branch
  $ hg merge some-branch
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
hg commit (no reopening of some-branch)
  $ hgcommit -m 'merge with closed branch'

  $ cd ..