Re: [ANNOUNCE] tig-0.14

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

Jeff King <peff@peff.net> writes:

> My impression is that tig is currently doing (1).  I think (2) will
> suffer from the same problem, but in practice the margin of error will
> be much smaller because your are rewinding through fewer changes. So if
> that is what you were suggesting, I think it is probably worth trying.

It has been quite a while since I did the "show previous" feature of
"git-blame --porcelain" that has been forever queued in 'next'; if I
remember correctly, it implemented (2).

The reason why it never graduated from 'next' is exactly this issue.  By
definition, there is no "previous" line number (if there were such a thing
that says "This line was at line N in the parent of the blamed commit",
then the commit wouldn't have taken the blame but would have passed it
down to the parent), and we need to come up with a reasonable heuristics.

So perhaps this discussion would motivate somebody to finish that part
off, and tig and other Porcelains can just read the necessary line number
from the git-blame output.