Re: difflame

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Tue, Jan 17, 2017 at 11:24:02PM -0600, Edmundo Carmona Antoranz wrote:
>
>> For a very long time I had wanted to get the output of diff to include
>> blame information as well (to see when something was added/removed).
>
> This is something I've wanted, too. The trickiest part, though, is
> blaming deletions, because git-blame only tracks the origin of content,
> not the origin of a change.

Hmph, this is a comment without looking at what difflame does
internally, so you can ignore me if I am misunderstood what problem
you are pointing out, but I am not sure how "tracks the origin of
content" could be a problem.

If output from "git show" says this:

	--- a/file
	+++ b/file
	@@ -1,5 +1,6 @@
	 a
	 b
	-c
	+C
	+D
	 d
	 e

in order to annotate lines 'a', 'b', 'd', and 'e' for their origin,
you would run 'blame' on the commit the above output was taken from
(or its parent---they are in the context so either would be OK).

You know where 'C' and 'D' came from already.  It's the commit you
are feeding "git show".

In order to run blame to find where 'c' came from, you need to start
at the _parent_ of the commit the above output came from, and the
hunk header shows which line range to find the final 'c'.

So...