Re: Following renames

From: Linus Torvalds <torvalds@osdl.org>
Date: Mar 26, 2006, 23:09 UTC
Message-ID: <Pine.LNX.4.64.0603261505230.15714@g5.osdl.org>
In-Reply-To: <20060326223154.GU18185@pasky.or.cz>

On Mon, 27 Mar 2006, Petr Baudis wrote:

Show 9 quoted lines

> Dear diary, on Mon, Mar 27, 2006 at 12:22:04AM CEST, I got a letter
> where Linus Torvalds <torvalds@osdl.org> said that...
> > So commit "6" is uninteresting, and commit "5" will never even be
> > looked at, since we decided that the history of "d" comes from the
> > first parent with the same contents.
> 
> And this is the thing I have a problem with - this does not make much
> sense to me, why can't we just follow all parents instead of arbitrarily
> choosing one of them?

Sure, you can. It's _usually_ a huge waste of time, though. Why would you want to do more work than you need, since clearly the other parent was _not_ interesting from the standpoint of the question "where did this content come from"?

Show 5 quoted lines

> > No, it's the expected output just because you expected merges to always 
> > show up. Merges get ignored if any of the parents have the same content 
> > already.
> 
> Eek. Can I avoid that? What was the reason for choosing this behavior?

Huge efficiency gains.

Lookie here. Do

	gitk -- rev-list.c

on the git archive with the current git-rev-list, and with your hacked-up version.

And tell me my version isn't a hell of a lot better. Because, I guarantee you, it is. We're just not _interested_ in all those merges that didn't actually make any difference.

Read up on what modern neuro-science thinks about the human brain, and what a lot of it is about. It's about ignoring irrelevant information.

The ability to throw stuff out that isn't interesting is the _real_ basis of true intelligence. I'd rather have git do the _intelligent_ history, than show history that isn't relevant and workign harder doing so.

		Linus