Re: git-checkout changes the index but not the checked out files?

[Linus Torvalds <torvalds@linux-foundation.org>]

On Mon, 23 Apr 2007, Martin Langhoff wrote:
> 
> The _really_ strange bit is that it was attempting to merge 2 heads of
> the same name. It'd probably be something to block...

No, "git-read-tree -m A B" is not a "merge" in the sense you're thinking, 
it's a "fast-forward merge", ie just a "move from A to B"

So read-tree has three "merges": a one-way merge (which just merges with 
the old index _stat_ contents but otherwise just reads in the new tree), a 
two-way merge (a "move from A to B") that checks that all paths that are 
different in the two trees match the index in the old one, and the "real"
merge, aka the three-way thing (and even that is actially "four-way", 
since it also checks the index for matchingness)

So when we move from one head to another, we do that two-way thing. And if 
A and B are the same, doesn't really do anything, but there's also no 
point to try to avoid doing it.

		Linus