Re: Redisplay issue

[Yuan MEI]

> I have only one more idea: can you build Emacs without Cairo?  Cairo
> changes the way Emacs draws the screen in significant ways, and that
> is the only part of this puzzle that we didn't verify yet.  The traces
> indicate that everything up to the point where we invoke the drawing
> code is identical between the "good" and the "bad" cases, and
> correctly instructs the display back-end to redraw every screen line
> in the exposed region(s).

Very interesting.  The partial redraw problem seems to be gone when
cairo is disabled.  I couldn't reproduce the bad case any more.
However I encountered another bug when cairo is disabled: did C-h h to
bring up HELLO, and Emacs crashed:

lisp.h:1543: Emacs fatal error: assertion failed: 0 <= size
Fatal error 6: Aborted
lisp.h:1543: Emacs fatal error: assertion failed: 0 <= size
Aborted

Thanks,

Yuan