[PATCH 2 of 2 stable] rebase: handle rebasing of merges of destination ancestors

[Martin von Zweigbergk]

On Fri Nov 07 2014 at 5:28:34 PM Mads Kiilerich <mads at kiilerich.com> wrote:

> # HG changeset patch
> # User Mads Kiilerich <madski at unity3d.com>
> # Date 1415409531 -3600
> #      Sat Nov 08 02:18:51 2014 +0100
> # Branch stable
> # Node ID 4f80b7a3cdf219d1c8e5b3a7f2d539cd035cf8c4
> # Parent  8f689654b7d3d6b7c2b370cd5e38198b625e4fc6
> rebase: handle rebasing of merges of destination ancestors
>
> A situation with several merges from another branch can be 'straightened
> out'
> by rebasing (or grafting) on top of the other branch. One problem is merges
> that merges an ancestor of the rebase destination. Graft will skip such
> merges
> as 'ungraftable merge revision'. Rebase would try to rebase them ... and
> could
> fail.
>
> Now, the problem is solved by skipping such ancestor merges when rebasing.
>
> diff --git a/hgext/rebase.py b/hgext/rebase.py
> --- a/hgext/rebase.py
> +++ b/hgext/rebase.py
> @@ -547,7 +547,21 @@ def rebasenode(repo, rev, p1, state, col
>          base = repo[rev].p1().node()
>      else:
>          # In case of merge, we need to pick the right parent as merge
> base.
> -        #
> +
> +        margedancestors = list(repo.revs('parents(%d)&::%d',
> +                                         repo[rev].rev(), repo[p1].rev()))
> +        if margedancestors:
> +            repo.ui.warn(_('%s is merging %s which is an ancestor of '
> +                           'the rebase target and is ignored\n') %
> +                         (rev, margedancestors[0]))
> +            # TODO: If all ancestors all the way back to 'branching
> point' has
> +            # been rebased (no cherry picking), we could use
> +            #   base = repo[margedancestors[0]].node()
> +            # to use the merge snapshot as a checkpoint to verify that
> rebase
> +            # conflicts has been resolved as the merge conflicts was
> resolved.
> +            # If resolved the same way, the rebase of the merge willbe a
> noop.
> +            return None
> +
>          # Imagine we have:
>          # - M: currently rebase revision in this step
>          # - A: one parent of M
> diff --git a/tests/test-rebase-collapse.t b/tests/test-rebase-collapse.t
> --- a/tests/test-rebase-collapse.t
> +++ b/tests/test-rebase-collapse.t
> @@ -113,6 +113,7 @@ Rebasing E onto H:
>
>    $ hg phase --force --secret 6
>    $ hg rebase --source 4 --collapse
> +  6 is merging 5 which is an ancestor of the rebase target and is ignored
>    saved backup bundle to $TESTTMP/a2/.hg/strip-backup/*-backup.hg (glob)
>
>    $ hg tglog
> @@ -153,6 +154,7 @@ Rebasing G onto H with custom message:
>    > true
>    > EOF
>    $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --source 4
> --collapse -m 'custom message' -e
> +  6 is merging 5 which is an ancestor of the rebase target and is ignored
>    HGEDITFORM=rebase.collapse
>    saved backup bundle to $TESTTMP/a3/.hg/strip-backup/*-backup.hg (glob)
>
> diff --git a/tests/test-rebase-detach.t b/tests/test-rebase-detach.t
> --- a/tests/test-rebase-detach.t
> +++ b/tests/test-rebase-detach.t
> @@ -325,6 +325,7 @@ Verify that target is not selected as ex
>    $ hg ci -m "J"
>
>    $ hg rebase -s 8 -d 7 --collapse --config ui.merge=internal:other
> +  9 is merging 7 which is an ancestor of the rebase target and is ignored
>    saved backup bundle to $TESTTMP/a6/.hg/strip-backup/*-backup.hg (glob)
>
>    $ hg tglog
> diff --git a/tests/test-rebase-newancestor.t b/tests/test-rebase-
> newancestor.t
> --- a/tests/test-rebase-newancestor.t
> +++ b/tests/test-rebase-newancestor.t
> @@ -76,15 +76,11 @@ that often happens when trying to rebase
>    $ touch devstuff
>    $ hg ci -Aqm 'real dev stuff'
>    $ hg rebase -r 'branch(dev)' -d default
> -  remote changed f which local deleted
> -  use (c)hanged version or leave (d)eleted? c
> -  local changed f which remote deleted
> -  use (c)hanged version or (d)elete? c
> +  4 is merging 1 which is an ancestor of the rebase target and is ignored
> +  5 is merging 2 which is an ancestor of the rebase target and is ignored
>    saved backup bundle to $TESTTMP/repo2/.hg/strip-backup/*-backup.hg
> (glob)
>    $ hg tglog
> -  @  4: 'real dev stuff'
> -  |
> -  o  3: 'merge f stuff'
> +  @  3: 'real dev stuff'
>

It looks like the commit that creates the dev branch still gets lost. Is
that desirable? I don't see why it would be.


>    |
>    o  2: 'remove f'
>    |
> diff --git a/tests/test-rebase-scenario-global.t
> b/tests/test-rebase-scenario-global.t
> --- a/tests/test-rebase-scenario-global.t
> +++ b/tests/test-rebase-scenario-global.t
> @@ -117,6 +117,7 @@ E onto H - skip of G:
>    $ cd a3
>
>    $ hg rebase -s 4 -d 7
> +  6 is merging 5 which is an ancestor of the rebase target and is ignored
>    saved backup bundle to $TESTTMP/a3/.hg/strip-backup/*-backup.hg (glob)
>
>    $ hg tglog
> @@ -143,6 +144,7 @@ F onto E - rebase of a branching point (
>    $ cd a4
>
>    $ hg rebase -s 5 -d 4
> +  6 is merging 4 which is an ancestor of the rebase target and is ignored
>    saved backup bundle to $TESTTMP/a4/.hg/strip-backup/*-backup.hg (glob)
>
>    $ hg tglog
> _______________________________________________
> Mercurial-devel mailing list
> Mercurial-devel at selenic.com
> http://selenic.com/mailman/listinfo/mercurial-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://selenic.com/pipermail/mercurial-devel/attachments/20141108/b0ab3da4/attachment.html>