Re: [ANNOUNCE] Git wiki

[Linus Torvalds <torvalds@osdl.org>]

On Fri, 5 May 2006, Petr Baudis wrote:
> 
> The automatic vs. explicit movement tracking is a lot more
> controversial. Explicit movement tracking is pretty easy to provide for
> file-level movements, it's just that the user says "I _did_ move file
> A to file B" (I never got the Linus' argument that the user has no idea
> - he just _performed_ the move, also explicitly, by calling *mv).

THE USER DID NO SUCH THING.

Moving data around happens with a whole lot more than "mv".

It happens with patches (somebody _else_ may have done an "mv", without 
using git at all), and it happens with editors (moving data around until 
most of it exists in another file).

So doing "*mv" is just a special case.

And supporting special cases is _wrong_. If you start depending on data 
that isn't actually dependable, that's WRONG.

There's another reason why encoding movement information in the commit is 
totally broken, namely the fact that a lot of the actions DO NOT WALK THE 
COMMIT CHAIN!

Try doing

	git diff v1.3.0..

and think about what that actually _means_. Think about the fact that it 
doesn't actually walk the commit chain at all: it diffs the trees between 
v1.3.0 and the current one. What if the rename happened in a commit in the 
middle?

The "track contents, not intentions" approach avoids both these things. 
The end result is _reliable_, not a "random guess".

Adding file movement note to commits is simply WRONG.

Why does this come up every three months or so? I was right the first 
time. You'd think that as time passes, people would just notice more and 
more how right I was and am, instead of forgetting and bringing this 
idiotic idea up over and over and over again.

		Linus