[PATCH evolve-ext:stable] evolve: don't try to relocate a node on top of itself

[Pierre-Yves David]

On 03/25/2014 04:10 PM, Angel Ezquerra wrote:
> On Wed, Mar 26, 2014 at 12:06 AM, Olle Lundberg <olle.lundberg at gmail.com> wrote:
>> # HG changeset patch
>> # User Olle Lundberg <geek at nerd.sh>
>> # Date 1395788513 -3600
>> #      Wed Mar 26 00:01:53 2014 +0100
>> # Branch stable
>> # Node ID 5a2abe5bae7ae4f439d4a078b7891e3bcf6bcc48
>> # Parent  6a67606e1c3456c603707fe57e8404af5e33a1bd
>> evolve: don't try to relocate a node on top of itself
>>
>> This fixes problems with "no support for evolution merge changes yet"
>> on a linear repo, where evolve thinks that a node is supposed to be
>> relocated on top of itself.
>>
>> diff --git a/hgext/evolve.py b/hgext/evolve.py
>> --- a/hgext/evolve.py
>> +++ b/hgext/evolve.py
>> @@ -1007,36 +1007,39 @@
>>       targets = newer[0]
>>       assert targets
>>       if len(targets) > 1:
>>           raise util.Abort(_("does not handle split parents yet\n"))
>>           return 2
>> -    target = targets[0]
>> -    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
>> -    target = repo[target]
>> -    repo.ui.status(_('move:'))
>> -    if not ui.quiet:
>> -        displayer.show(orig)
>> -    repo.ui.status(_('atop:'))
>> -    if not ui.quiet:
>> -        displayer.show(target)
>> -    if progresscb: progresscb()
>> -    todo = 'hg rebase -r %s -d %s\n' % (orig, target)
>> -    if dryrun:
>> -        repo.ui.write(todo)
>> -    else:
>> -        repo.ui.note(todo)
>> -        if progresscb: progresscb()
>> -        lock = repo.lock()
>> -        try:
>> -            relocate(repo, orig, target)
>> -        except MergeFailure:
>> -            repo.opener.write('graftstate', orig.hex() + '\n')
>> -            repo.ui.write_err(_('evolve failed!\n'))
>> -            repo.ui.write_err(_('fix conflict and run "hg evolve --continue"\n'))
>> -            raise
>> -        finally:
>> -            lock.release()
>> +    target = repo[targets[0]]
>> +    # Target revision is same as original revision, it makes no sense to try
>> +    #  to relocate a node on top of itself.
>> +    if target.rev() != orig.rev()
>> +        displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
>> +        repo.ui.status(_('move:'))
>> +        if not ui.quiet:
>> +            displayer.show(orig)
>> +        repo.ui.status(_('atop:'))
>> +        if not ui.quiet:
>> +            displayer.show(target)
>> +        if progresscb:
>> +            progresscb()
>> +        todo = 'hg rebase -r %s -d %s\n' % (orig, target)
>> +        if dryrun:
>> +            repo.ui.write(todo)
>> +        else:
>> +            repo.ui.note(todo)
>> +            if progresscb: progresscb()
>> +            lock = repo.lock()
>> +            try:
>> +                relocate(repo, orig, target)
>> +            except MergeFailure:
>> +                repo.opener.write('graftstate', orig.hex() + '\n')
>> +                repo.ui.write_err(_('evolve failed!\n'))
>> +                repo.ui.write_err(_('fix conflict and run "hg evolve --continue"\n'))
>> +                raise
>> +            finally:
>> +                lock.release()
>>
>>   def _solvebumped(ui, repo, bumped, dryrun=False, progresscb=None):
>>       """Stabilize a bumped changeset"""
>>       # For now we deny bumped merge
>>       if len(bumped.parents()) > 1:
>
> Wouldn't it be better to just do the check and exit early (showing
> some error message), and keep the rest of the code the same? That
> would be a much smaller patch.

What angel say, In theory, this should not happen at all. So the current 
step is to move from

- I'm happily performing a non-sense operation

to

- I detect this is non-sense and abort before doing anything bad.
   Informing the user he hit a bad bad an must use rebase by himself to 
solve the situation.

You current patch make a bad error  silent and this is bad bad bad

Thanks for looking at it however.

-- 
Pierre-Yves