[PATCH 2 of 2 V2] strip: take branch into account when selecting update target (issue5540)

[Matt Harbison]

On Fri, 06 Oct 2017 12:17:17 -0400, Paul Morelle  
<paul.morelle at octobus.net> wrote:

> # HG changeset patch
> # User Paul Morelle <paul.morelle at octobus.net>
> # Date 1507212785 -7200
> #      Thu Oct 05 16:13:05 2017 +0200
> # Node ID 18c8fa9b75ba1c7b0dfd984cf78d35d0a467ab24
> # Parent  ae82f66cd58f85264e756f7a718ae9fbae5f17db
> # EXP-Topic issue-5540
> # Available At https://bitbucket.org/octobus/mercurial-devel/
> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r  
> 18c8fa9b75ba
> strip: take branch into account when selecting update target (issue5540)
>
> Test contributed by Matt Harbison
>
> Keep the same behavior in most cases (i.e. first parent of the first  
> root of
> stripped changsets), but if the branch differs from wdir's, try to find  
> another
> parent of stripped commits that is on the same branch.
>
> diff -r ae82f66cd58f -r 18c8fa9b75ba hgext/strip.py
> --- a/hgext/strip.py	Thu Oct 05 15:11:34 2017 +0200
> +++ b/hgext/strip.py	Thu Oct 05 16:13:05 2017 +0200
> @@ -60,10 +60,18 @@
> def _find_update_target(repo, revs):
>      urev, p2 = repo.changelog.parents(revs[0])
> +    current_branch = repo[None].branch()
>     if (util.safehasattr(repo, 'mq') and p2 != nullid
>          and p2 in [x.node for x in repo.mq.applied]):
>          urev = p2
> +    elif current_branch != repo[urev].branch():
> +        revset = "(parents(%ln::parents(wdir())) -  
> %ln::parents(wdir()))" \
> +                 + " and branch(%s)"
> +        branch_targets = repo.revs(revset, revs, revs, current_branch)
> +        if branch_targets:
> +            cl = repo.changelog
> +            urev = min(cl.node(r) for r in branch_targets)

Should this be max() instead of min(), to get the node closest to wdir?   
Updating way back might be surprising.  I didn't try making a more  
elaborate test, so maybe not.  I'm thinking, for example, developer A  
keeps pulling and merging from developer B, both using the same named  
branch.  Then strip the first merge.

>     return urev
> diff -r ae82f66cd58f -r 18c8fa9b75ba tests/test-strip.t
> --- a/tests/test-strip.t	Thu Oct 05 15:11:34 2017 +0200
> +++ b/tests/test-strip.t	Thu Oct 05 16:13:05 2017 +0200
> @@ -941,6 +941,146 @@
>    abort: boom
>    [255]
> +test stripping a working directory parent doesn't switch named branches
> +
> +  $ hg log -G
> +  @  changeset:   1:eca11cf91c71
> +  |  tag:         tip
> +  |  user:        test
> +  |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  |  summary:     commitB
> +  |
> +  o  changeset:   0:105141ef12d0
> +     user:        test
> +     date:        Thu Jan 01 00:00:00 1970 +0000
> +     summary:     commitA
> +
> +
> +  $ hg branch new-branch
> +  marked working directory as branch new-branch
> +  (branches are permanent and global, did you want a bookmark?)
> +  $ hg ci -m "start new branch"
> +  $ echo 'foo' > foo.txt
> +  $ hg ci -Aqm foo
> +  $ hg up default
> +  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
> +  $ echo 'bar' > bar.txt
> +  $ hg ci -Aqm bar
> +  $ hg up new-branch
> +  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
> +  $ hg merge default
> +  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
> +  (branch merge, don't forget to commit)
> +  $ hg ci -m merge
> +  $ hg log -G
> +  @    changeset:   5:4cf5e92caec2
> +  |\   branch:      new-branch
> +  | |  tag:         tip
> +  | |  parent:      3:f62c6c09b707
> +  | |  parent:      4:35358f982181
> +  | |  user:        test
> +  | |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  | |  summary:     merge
> +  | |
> +  | o  changeset:   4:35358f982181
> +  | |  parent:      1:eca11cf91c71
> +  | |  user:        test
> +  | |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  | |  summary:     bar
> +  | |
> +  o |  changeset:   3:f62c6c09b707
> +  | |  branch:      new-branch
> +  | |  user:        test
> +  | |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  | |  summary:     foo
> +  | |
> +  o |  changeset:   2:b1d33a8cadd9
> +  |/   branch:      new-branch (glob)

Windows doesn't like this glob, and Linux seems OK without it too.

> +  |    user:        test
> +  |    date:        Thu Jan 01 00:00:00 1970 +0000
> +  |    summary:     start new branch
> +  |
> +  o  changeset:   1:eca11cf91c71
> +  |  user:        test
> +  |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  |  summary:     commitB
> +  |
> +  o  changeset:   0:105141ef12d0
> +     user:        test
> +     date:        Thu Jan 01 00:00:00 1970 +0000
> +     summary:     commitA
> +
> +
> +  $ hg strip -r 35358f982181

If I comment out the commit for the merge above the DAG and use --force on  
this strip, it updates to eca11cf91c71.  I'd expect it to still update to  
f62c6c09b707, since that's the same named branch.

> +  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
> +  saved backup bundle to  
> $TESTTMP/issue4736/.hg/strip-backup/35358f982181-a6f020aa-backup.hg  
> (glob)
> +  $ hg log -G
> +  @  changeset:   3:f62c6c09b707
> +  |  branch:      new-branch
> +  |  tag:         tip
> +  |  user:        test
> +  |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  |  summary:     foo
> +  |
> +  o  changeset:   2:b1d33a8cadd9
> +  |  branch:      new-branch
> +  |  user:        test
> +  |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  |  summary:     start new branch
> +  |
> +  o  changeset:   1:eca11cf91c71
> +  |  user:        test
> +  |  date:        Thu Jan 01 00:00:00 1970 +0000
> +  |  summary:     commitB
> +  |
> +  o  changeset:   0:105141ef12d0
> +     user:        test
> +     date:        Thu Jan 01 00:00:00 1970 +0000
> +     summary:     commitA
> +