[PATCH 1 of 2] update: warn about other topological heads on bare update

[Pierre-Yves David]

On 02/05/2016 04:52 PM, Yuya Nishihara wrote:
> On Wed, 03 Feb 2016 17:43:59 +0000, Pierre-Yves David wrote:
>> # HG changeset patch
>> # User Pierre-Yves David <pierre-yves.david at fb.com>
>> # Date 1454424542 0
>> #      Tue Feb 02 14:49:02 2016 +0000
>> # Node ID d61062a8e69c5586171a9207994c13dfc69ea975
>> # Parent  8e79ad2da8a69735488402fd018dd82bc1eb9309
>> # EXP-Topic destination
>> # Available At http://hg.netv6.net/marmoute-wip/mercurial/
>> #              hg pull http://hg.netv6.net/marmoute-wip/mercurial/ -r d61062a8e69c
>> update: warn about other topological heads on bare update
>>
>> A concern around the user experience of Mercurial is user getting stuck on there
>> own topological branch forever. For example, someone pulling another topological
>> branch, missing that message in pull asking them to merge and getting stuck on
>> there own local branch.
>>
>> The current way to "address" this concern was for bare 'hg update' to target the
>> tipmost (also latest pulled) changesets and complain when the update was not
>> linear. That way, failure to merge newly pulled changesets would result in some
>> kind of failure.
>>
>> Yet the failure was quite obscure, not working in all cases (eg: commit right
>> after pull) and the behavior was very impractical in the common case
>> (eg: issue4673).
>>
>> To be able to change that behavior, we need to provide other ways to alert a
>> user stucks on one of many topological head. We do so with an extra message after
>> bare update:
>>
>>    1 other heads for branch "default"
>>
>> Bookmark get its own special version:
>>
>>    %i other divergent bookmarks for "%s"\n
>
>> +def _statusotherbook(ui, repo):
>> +    bmheads = repo.bookmarkheads(repo._activebookmark)
>> +    curhead = repo[repo._activebookmark].node()
>> +    if repo.revs('%n - parents()', curhead):
>> +        # we are on the active bookmark
>> +        bmheads = [b for b in bmheads if curhead == bmheads[0]]
>> +        if 1 < len(bmheads):
>> +            msg = _('%i other divergent bookmarks for "%s"\n')
>> +            ui.status(msg % (len(bmheads), repo._activebookmark))
>
> This isn't covered by tests?
> It seems wrong in that bmheads is filtered by curhead == bmheads[0].

Hum apparently there is no remaining test covering this. Something went 
wrong. I'll add one and follow up with a V2.

-- 
Pierre-Yves David