Re: Adding fake cursors when resizing a window.

[Eli Zaretskii]

> Date:  Thu, 07 Mar 2019 17:39:20 -0800
> From:  Keith David Bershatsky <address@hidden>
> Cc:  address@hidden,Martin Rudalics <address@hidden>
> 
> I am able to observe the behavior described on Emacs for w32 and NS, but 
> _not_ running on X11 with the current build settings.
> 
> I have set up stderr messages in all locations where draw_glyphs is called 
> and have concluded that draw_glyphs is _not_ responsible for erasing the fake 
> cursors along the vertical strip that forms the scroll bar in the middle of 
> the screen (which gets removed when the right window is deleted, and the left 
> window increases to fill the entire frame).  In addition to the stderr 
> messages, I can visually see that the gap left in the area of fake cursors is 
> the same width as the vertical scroll bar, and the gap does not align exactly 
> with two characters.  In other words, if draw_glyphs were somehow responsible 
> for erasing the fake cursors in the area affected, then the fake cursors 
> would be removed at the same X-axis and exact pixel width of each new 
> character that gets drawn on the glass.

Step through the code starting at the point where you redraw the fake
cursors, and see what happens.  Maybe some later operation erases
them, or something.