[cairo] Who wants to help make "line width locking" happen?

[Carl Worth]

We've had an item on cairographics.org/todo about implementing "pen
matrix locking" for quite a while. Bill just tracked down a thread I
started long ago pointing out the first time I noticed the issue:

Adventures in line widths
http://lists.cairographics.org/archives/cairo/2006-April/006790.html

And I found another one where I proposed some patches just before the
1.2 release:

Problems with cairo_get_line_width and "new" semantics
http://lists.cairographics.org/archives/cairo/2006-May/006948.html

(I've just linked to both of these on the "todo" and added some
commentary, which I wanted to share with the whole community:)

The history there is that I was working hard to fix in the 1.2 release
what I saw as a big semantic bug in cairo 1.0. But this was also too
disruptive a change very late in the cycle, and I also feared
introducing problems by breaking backward compatibility. So nothing has
changed, (not in 1.2, 1.4, nor 1.6).

Today, I'd still like to make it easy to get the "new" behavior. We'll
probably need to make it so that the user can explicitly request it
somehow, but that old code continues to work as it always did. I'm not
sure. But I'm definitely hoping that someone other than me will step up
and argue for something, (with code in hand---even if its mostly code I
originally wrote). I'd much rather review and "bless" something than try
to push for a change here myself.

Anyone up for that?

-Carl