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

[Michael Hudson]

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.

Cheers,
mwh