On Fri, Feb 18, 2011 at 4:26 PM, Linus Torvalds
[off-list ref] wrote:
So please consider the attached patch just a "look, guys, this is
wrong, and here's the ugliest hack you've ever seen to fix it".
Btw, the more I think about it, the more I suspect that the
"estimate_similarity()" part of the patch is correct, or at least
better than what we used to have.
If we have a file that expanded from 100 lines to 200 lines, and all
of the old contents are there, then I think that logically people
would expect it to be a "50% similarity".
But the thing is, with the old code, we would look at the old smaller
size (100 lines), and take 50% of that. And then when the delta (also
100 lines) is bigger than that 50%, then we'd totally dismiss that
thing from similarity analysis, because it obviously isn't similar
enough.
So using the bigger size as the basis (and taking 50% of _that_ and
comparing it to the delta) is probably the sane thing to do.
The rest of the patch I still think is total crap. The _intention_ is
good, but the patch was written to be small rather than the right way
of doing things.
Linus