Re: Changes in frame/window code

[martin rudalics]

> I don't see the relevance of 18277 to this issue.  That bug is about
> clicking inside the text area, not about clicking on the scroll bar or
> hscrolling.  Why do you think they are related?

Because clicking changes the hscroll amount.

 I could be wrong, but I don't think they are related to 18277 at all.
> E.g., there's nothing in common between vertical-motion (which is what
> you do in (3)) and moving point by clicking the mouse.

Apparently vertical motion with partially scrolled text affects hscroll
in some strange way.

> As for 2, does this happen around line 655?  That line, and the one
> that follows, are L2R, and so are lines 918 and 919.  This could
> confuse the code.  Another possible reason could be short lines that
> disappear entirely under some large enough hscroll.

AFAICT neither of these are involved.  But I suppose that quite often
embedded L2R text is involved.

> To summarize, I think you should commit your changes, and we should
> deal with the fallout with later commits.  After all, these problems
> went unnoticed until now, and they only happen if one turns on
> truncate-lines in the tutorial, which sounds an unlikely situation.
> It makes little sense to me to delay the horizontal scroll-bar fixes
> due to these anomalies, which are unlikely to be related to your
> un-installed changes.

OK.  I installed the changes so that they should work for the Windows
build (I don't want to mangle the other builds at this stage).  Please
have a look at the three problems from my last post.

Note: Problem (3) is reproducible only in the left of two side-by-side
windows.  Since this is the strangest bug maybe you could have a look.
I'll repeat how to reproduce it.  Load the tutorial, split the window
via C-x 3.  In the left window move point to the rightmost column of
bidi text before line 121.  Lean on your `next-line' key until you reach
line 121 - here redisplay hangs.  I can't reproduce this with any other
line.

martin