[MERGE] special case the no-args version of revision-info

[Michael Hudson]

Michael Hudson wrote:
> Ian Clatworthy wrote:
>> Michael Hudson wrote:
>>> Reading this post:
>>>
>>> http://blog.orebokech.com/2008/03/emacs-in-bzr-initial-impressions.html
>>>
>>> I was prompted to look at the implementation of version-info.  It seems
>>> to be a bit whole-history happy: RevisionSpec.in_branch calls
>>> revsion_history() and the command implementation calls
>>> get_revid_to_revno_map().
>>>
>>> This bundle just makes it really fast for the no-arg case.  Perhaps it
>>> would be better to improve the interpretation of "revno:-$SMALLINT".
>>
>> Trying your patch on bzr.dev, it doesn't seem to make much difference to
>> the results of 'time bzr version-info'. Maybe I'm doing something wrong.
>> What speed-up are you seeing?
> 
> Oh, I should have said: on emacs, 6s -> 0.2s.

Sorry for the fast follow-up: I think this is a branch5/branch6 thing. 
bzr.dev is branch5, the emacs import is branch6.

Cheers,
mwh