[PATCH 06 of 11] copies: update _checkcopies to work in a rotated DAG (issue4028)

[Pierre-Yves David]

On 10/04/2016 04:39 PM, Gábor Stefanik wrote:
> # HG changeset patch
> # User Gábor Stefanik <gabor.stefanik at nng.com>
> # Date 1475588213 -7200
> #      Tue Oct 04 15:36:53 2016 +0200
> # Node ID a1b8ff5837d36693338b51966dd92249e728cba2
> # Parent  bc8729a69d10d61498712d5dab773918f1edcde0
> copies: update _checkcopies to work in a rotated DAG (issue4028)

This change is an important step in your fixes, can you elaborate a bit 
more in the description about what is happening?

> diff -r bc8729a69d10 -r a1b8ff5837d3 mercurial/copies.py
> --- a/mercurial/copies.py	Mon Oct 03 13:29:59 2016 +0200
> +++ b/mercurial/copies.py	Tue Oct 04 15:36:53 2016 +0200
> @@ -345,10 +345,12 @@
>      bothnew = sorted(addedinm1 & addedinm2)
>
>      for f in u1u:
> -        _checkcopies(c1, f, m1, m2, ca, limit, diverge, copy1, fullcopy1)
> +        _checkcopies(c1, f, m1, m2, ca, ca, False, limit, diverge, copy1,
> +                     fullcopy1)
>
>      for f in u2u:
> -        _checkcopies(c2, f, m2, m1, ca, limit, diverge, copy2, fullcopy2)
> +        _checkcopies(c2, f, m2, m1, ca, ca, False, limit, diverge, copy2,
> +                     fullcopy2)
>
>      copy = dict(copy1.items() + copy2.items())
>      movewithdir = dict(movewithdir1.items() + movewithdir2.items())
> @@ -373,8 +375,10 @@
>                        % "\n   ".join(bothnew))
>      bothdiverge, _copy, _fullcopy = {}, {}, {}
>      for f in bothnew:
> -        _checkcopies(c1, f, m1, m2, ca, limit, bothdiverge, _copy, _fullcopy)
> -        _checkcopies(c2, f, m2, m1, ca, limit, bothdiverge, _copy, _fullcopy)
> +        _checkcopies(c1, f, m1, m2, ca, ca, False, limit, bothdiverge, _copy,
> +                     _fullcopy)
> +        _checkcopies(c2, f, m2, m1, ca, ca, False, limit, bothdiverge, _copy,
> +                     _fullcopy)
>      for of, fl in bothdiverge.items():
>          if len(fl) == 2 and fl[0] == fl[1]:
>              copy[fl[0]] = of # not actually divergent, just matching renames
> @@ -454,7 +458,8 @@
>
>      return copy, movewithdir, diverge, renamedelete
>
> -def _checkcopies(ctx, f, m1, m2, ca, limit, diverge, copy, fullcopy):
> +def _checkcopies(ctx, f, m1, m2, ca, tca, remoteca, limit, diverge, copy,
> +                 fullcopy):
>      """
>      check possible copies of f from m1 to m2
>
> @@ -462,7 +467,9 @@
>      f = the filename to check
>      m1 = the source manifest
>      m2 = the destination manifest
> -    ca = the changectx of the common ancestor
> +    ca = the changectx of the common ancestor, overridden on graft
> +    tca = topological common ancestor for graft-like scenarios
> +    remoteca = True if ca is outside tca::ctx, False otherwise
>      limit = the rev number to not search beyond
>      diverge = record all diverges in this dict
>      copy = record all non-divergent copies in this dict
> @@ -475,6 +482,8 @@
>      """
>
>      ma = ca.manifest()
> +    mta = tca.manifest()
> +    backwards = ca != tca and not remoteca and f in ma
>      getfctx = _makegetfctx(ctx)
>
>      def _related(f1, f2, limit):
> @@ -520,15 +529,26 @@
>              continue
>          seen.add(of)
>
> -        fullcopy[f] = of # remember for dir rename detection
> +        # remember for dir rename detection
> +        if backwards:
> +            fullcopy[of] = f # grafting backwards through renames
> +        else:
> +            fullcopy[f] = of
>          if of not in m2:
>              continue # no match, keep looking
>          if m2[of] == ma.get(of):
>              return # no merge needed, quit early
>          c2 = getfctx(of, m2[of])
> -        cr = _related(oc, c2, ca.rev())
> +        cr = _related(oc, c2, tca.rev())
>          if cr and (of == f or of == c2.path()): # non-divergent
> -            copy[f] = of
> +            if backwards:
> +                copy[of] = f
> +            elif of in ma:
> +                copy[f] = of
> +            elif remoteca: # special case: a <- b <- a -> b "ping-pong" rename
> +                copy[of] = f
> +                del fullcopy[f]
> +                fullcopy[of] = f
>              return
>
>      if of in ma:
> diff -r bc8729a69d10 -r a1b8ff5837d3 tests/test-graft.t
> --- a/tests/test-graft.t	Mon Oct 03 13:29:59 2016 +0200
> +++ b/tests/test-graft.t	Tue Oct 04 15:36:53 2016 +0200
> @@ -427,8 +427,8 @@
>    $ hg graft 3 --log -u foo
>    grafting 3:4c60f11aa304 "3"
>    warning: can't find ancestor for 'c' copied from 'b'!
> -  $ hg log --template '{rev} {parents} {desc}\n' -r tip
> -  14 1:5d205f8b35b6  3
> +  $ hg log --template '{rev}:{node|short} {parents} {desc}\n' -r tip
> +  14:0c921c65ef1e 1:5d205f8b35b6  3
>    (grafted from 4c60f11aa304a54ae1c199feb94e7fc771e51ed8)
>
>  Resolve conflicted graft
> @@ -620,7 +620,7 @@
>    date:        Thu Jan 01 00:00:00 1970 +0000
>    summary:     2
>
> -  changeset:   14:f64defefacee
> +  changeset:   14:0c921c65ef1e
>    parent:      1:5d205f8b35b6
>    user:        foo
>    date:        Thu Jan 01 00:00:00 1970 +0000
>
>
>
> _______________________________________________
> Mercurial-devel mailing list
> Mercurial-devel at mercurial-scm.org
> https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
>

-- 
Pierre-Yves David