[PATCH 1 of 4] pull: work as usual bare "hg update" for URL#BRANCH

[Yuya Nishihara]

On Sun, 21 Feb 2016 21:22:42 +0900, FUJIWARA Katsunori wrote:
> 
> (CC-ed to Pierre-Yves and Ryan for suggestion from point of view of
> DefaultDestinationPlan)
> 
> At Sun, 21 Feb 2016 13:17:14 +0900,
> Yuya Nishihara wrote:
> > 
> > On Sun, 21 Feb 2016 03:31:30 +0900, FUJIWARA Katsunori wrote:
> > > At Sat, 20 Feb 2016 16:05:32 +0900,
> > > Yuya Nishihara wrote:
> > > > On Thu, 18 Feb 2016 04:49:25 +0900, FUJIWARA Katsunori wrote:
> > > > > # HG changeset patch
> > > > > # User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
> > > > > # Date 1455738388 -32400
> > > > > #      Thu Feb 18 04:46:28 2016 +0900
> > > > > # Node ID 4da9702b2eef28a1c6097f5dbce322bec8925fcd
> > > > > # Parent  95bf01b8754016200a99fd3538e78030b2028c60
> > > > > pull: work as usual bare "hg update" for URL#BRANCH
> > > > > 
> > > > > Ordinarily, "hg pull -u" works as same as "hg pull" + bare "hg update"
> > > > > (without any explicit revision), for example:
> > > > > 
> > > > >   - advance current active bookmark, if the destination of the update
> > > > >     is valid for 'bookmarks.validdest()'
> > > > > 
> > > > >   - update not to branch tip but to active bookmark, if the latter is
> > > > >     already updated at pulling changes
> > > > > 
> > > > > But before this patch, "hg pull -u" for "URL#BRANCH" doesn't work as
> > > > > expected.
> > > > > 
> > > > >   - current active bookmark is never advanced
> > > > > 
> > > > >   - update to branch tip always
> > > > > 
> > > > > This seems not reasonable for a user, who works on the branch "BRANCH"
> > > > > in the repo cloned by "URL#BRANCH".
> > > > > 
> > > > > But, on the other hand, if "hg pull" is executed with explicit
> > > > > --branch/--rev, or "URL#ANOTHER-BRANCH" source, this behavior seems
> > > > > reasonable, because user would want to update to specified revision
> > > > > (or branch tip).
> > > > > 
> > > > > This patch treats updating at "hg pull -u" as bare "hg update", if:
> > > > > 
> > > > >   - no --branch/--rev is specified, and
> > > > >   - current branch name is equal to "fragment" of "URL#fragment"
> > > > > 
> > > > > In this case, 'checkout = None' makes postincoming() use
> > > > > destutil.destupdate() to calculate the destination of the update and
> > > > > the bookmark to be advanced, as same as usual bare "hg update".
> > > > 
> > > > New behavior makes more sense to me, but I don't think "pull -u -bBRANCH URL"
> > > > should be different from "pull -u URL#BRANCH". Also, it is surprising that
> > > > "pull -u URL#BRANCH" does update to BRANCH tip if wdir is not at BRANCH.
> > > > 
> > > >   $ hg clone URL#A foo
> > > >   $ cd foo
> > > >   $ hg pull -u  # takes me to max(.::(head() and branch(A)))
> > > >   $ hg branch B
> > > >   $ hg ci
> > > >   ... doing lots of works ...
> > > >   $ hg pull -u  # why switching to the branch A?
> > > > 
> > > > If we go this direction, I think "pull -u" should always select the default
> > > > update destination, er, unless -rREV is specified?
> > > 
> > > Would you mean that both of "-b BRANCH" or "URL#fragment" doesn't
> > > affect to determining the destination of the update ?
> > 
> > Or always affects no matter if wdir is BRANCH or not. It seems confusing for
> > me to switch "hg update" and "hg update BRANCH" by dirstate.branch().
> > 
> >  a) "hg pull -bB -u" == "hg pull -bB && hg update B"
> >  b) "hg pull -bB -u" == "hg pull -bB && hg update"
> > 
> > My opinion is (a) or (b) should be selected statically, not dynamically based
> > on current branch.
> 
> I think that current updating behavior of "pull -u" below is
> reasonable in ordinary case, because user would want to update to
> specified one immediately. So, I like (a) above.
> 
>   - update to specified revision (or the tipmost branch head),
>     if -r REV, -b BRANCH, or URL#X is specified
> 
>   - otherwise, update like as bare "update"
> 
> A main concern of this patch is:
> 
>   even in the repo cloned via "URL#X", "pull -u" treats "#X" not as a
>   part of "default" pulling source, but a kind of "-r X"
> 
>   => active bookmark isn't advanced as expected

Hmm, if "pull -u URL#X" is "pull && update X", I think that's okay.

FWIW, I heard we plan to change "hg update" not to move the active bookmark.
This patch series would hit the hot topic that I don't know well.

>   => branch might be switched unintentionally, as you described in
>      previous reply above
> 
> Therefore, what about another solution below, even though this is a
> kind of "dynamic" one, too ?
> 
>   - update like as bare "update", if "[paths] default" and pulling
>     source have same fragment part

Uh, do you mean only the default path#fragment is handled specially?
That would be confusing because the default path is just one of the stocked
paths.

>     (we might have to compare also between "#fragment" and "-b
>     BRANCH", for similarity)
> 
>   - otherwise, update to specified fragment