From: Thomas Rast <trast@student.ethz.ch>
Date: Thu, 08 Apr 2010 16:27:22 GMT
Subject: Re: [PATCH 1/2] Add a basic idea section for git-blame.
Message-ID: <201004081827.22706.trast@student.ethz.ch>
In-Reply-To: <7vmxxe74s2.fsf@alter.siamese.dyndns.org>

Junio C Hamano wrote:
> Bo Yang <struggleyb.nku@gmail.com> writes:
> 
> > +A call to `git-blame <rev> -- <file>` works as follows:
> > +
> > +- Look at `git diff <rev>^ <rev>` to see what the commit did.
> > +
> > +- Discard all `-` lines in the diff, since they are no longer part of
> > +  `<file>`.
> > +
> > +- Take blame for all `+` lines; i.e., the newly added lines according
> > +  to the diff are attributed to `<rev>`.
> 
> I hate to say it, but this is horrifying; it works quite the other way
> around.
> 
> The name of the game is not "take blame by looking at the diff to see what
> we introduced"; it is "avoid taking blame at all cost, by looking at the
> diff to see what we might have inherited from our parents".

"Horrifying" seems a fairly harsh word for another way to describe the
process *in linear history* and with default settings, doesn't it?

I now see that "assume linear history" is oversimplifying the process,
but I have to take blame^W^W^W^Wwill fail to shift blame for it since
I suggested that.

> For illustrated description, read the classic:
>  
>     http://thread.gmane.org/gmane.comp.version-control.git/28826
> 
> Almost all the hits in the first page from this query would help, too:
> 
> http://search.gmane.org/?query=On+blame%2Fpickaxe&author=Junio+C+Hamano&group=gmane.comp.version-control.git&sort=revdate&DEFAULTOP=and&[=2&xP=blame%09pickaxe&xFILTERS=Gcomp.version-control.git-Ac-Ahamano-Ajunio---A

Thanks.  I trust this will help Bo make a revised description for the
manpage.



[PS for the list record: while part of the patches is indeed mine, I
never signed off on them.]

-- 
Thomas Rast
trast@{inf,student}.ethz.ch