Re: detecting rename->commit->modify->commit

From: Jeff King <peff@peff.net>
Date: May 1, 2008, 15:20 UTC
Message-ID: <20080501152035.GB11145@sigill.intra.peff.net>
In-Reply-To: <4819DCF1.7090504@tikalk.com>

On Thu, May 01, 2008 at 06:08:33PM +0300, Ittay Dror wrote:

> But it doesn't work across directories :-(.

Yes, it does.

Show 16 quoted lines

> Try:
> >mkdir foo
> >echo "hello" > foo/A
> >git add foo/A
> >git commit -m 'foo/A'
> >mkdir bar
> >git mv foo/A bar
> >git commit -m 'bar/A'
> >echo "world" >> bar/A
> >git add bar/A
> >git commit -m 'bar/A world'
> >git diff HEAD^^..HEAD^ | cat
> diff --git a/foo/A b/bar/A
> similarity index 100%
> rename from foo/A
> rename to bar/A

See, it just worked across directories.

Show 16 quoted lines

> > git diff HEAD^^.. | cat
> diff --git a/bar/A b/bar/A
> new file mode 100644
> index 0000000..94954ab
> --- /dev/null
> +++ b/bar/A
> @@ -0,0 +1,2 @@
> +hello
> +world
> diff --git a/foo/A b/foo/A
> deleted file mode 100644
> index ce01362..0000000
> --- a/foo/A
> +++ /dev/null
> @@ -1 +0,0 @@
> -hello

Of course it doesn't work here. You have two files, one containing "hello\n" and one containing "hello\nworld\n". Their similarity is 50%, which is not enough to consider it a rename. And I would argue that's reasonable, since the files have only one line in common. The problem is that you are using a toy example (which is why my example used /usr/share/dict/words, which has enough content to definitively call it a rename).

...

Hmm, looking at the code, though, 50% is supposed to be the default minimum. So there might actually be a bug.

-Peff