Re: Please don't use revision numbers on commit messages (and elsewhere).

[Uday S Reddy <u.s.reddy@cs.bham.ac.uk>]

On 4/2/2011 2:47 PM, Óscar Fuentes wrote:

>
>> The branch-local-revision is the localized version of the revision
>> number, i.e., 1 = 11-10, 2 = 12-10, ...
>>
>> So, doing that bit of arithmetic is all it takes to decode "revision 11".
>
> Yes, that works as long as those commits are merged in the same
> operation.

I think it always works independent of how you merge.  The local 
revision 11 will always be 10.x.1 and local revision 12 will always be 
10.x.2.  Whether you merge in one steps or multiple steps doesn't make a 
difference.

> But even on that case we would be better without the arithmetic. Think a
> feature branch with dozens or hundreds of commits. And I'm not talking
> just about commit messages. References on bug reports or e-mail
> exchanges suffer from the same.

In that case, you are talking about a tradeoff, what will be easier to 
the committer versus what will be easier for somebody to analyze things 
later on.  My feeling is that committing is done much more often and 
doing additional chores in the middle of committing is distracting.  So 
I would want to make it easier for committing.

If one states the branch nickname and the original revision id on the 
branch, then it can always be found on the trunk after merging.  You can 
find the branch nickname in the log and then do the little bit of 
arithmetic to find the right revision.

When bug reports are submitted for a branch, the Emacs reporter should 
be including the branch nickname as part of the version information (if 
it isn't doing so already).  That would ensure that the context is included.

> My branch log doesn't show the revnos of trunk as they are on trunk, but
> some renumbered version. As you mention, I can start counting merged
> revisions across merge points until reaching the referenced revision,
> but that's impractical.

Every revision is marked by the branch nick(name) and a revision number. 
  If the branch nick is stated as "trunk" for a top-level revision then 
it is the revision number on the trunk.  Otherwise, it is your local 
revision which would again be identified by your branch nick.

There is no counting involved.  A maximum of one addition or subtraction.

And, it should also be easy enough to write an Emacs command or two to 
automate it.

Cheers,
Uday