bug#10304: 24.0.92: display bug

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Magne Ingebrigtsen <larsi@gnus.org>
> Cc: 10304@debbugs.gnu.org
> Date: Sat, 15 Nov 2014 16:41:23 +0100
> 
> Ok, here are the two new traces.  The first one is when everything is OK.

Sorry for a long delay.

Unfortunately, I cannot match either of your two images with the
corresponding dump of the glyph matrix: there are small
inconsistencies in both the "OK" and the "not OK" cases.  For example,
the first image shows "Top L1" in the mode line of the window that
displays the article, but the matrix dump says:

 68: (1) ' 1:---  . news:g.c.w.arnoldzwicky Austenian humbleb...   Top L19    (Article)    '

which is line 19.  This is a minor discrepancy, but since there are
many similar discrepancies, some of which are probably parts of the
bug, I feel I have no firm ground from which I can begin studying the
data and making hypotheses about what went wrong.

Could you please produce 2 sets of screenshot+matrix dump which are
coherent with each other?  I must be sure that when I see a
discrepancy, it is part of the bug, not some artifact that needs to be
ignored.

Also, I don't understand the second screenshot: which parts of it are
correct and which are bogus?  The text before the image looks
unfinished, but its continuation, starting with screen line 20, which
is clearly present in the glyph matrix dump, is not shown.  Are you
saying that Emacs was supposed to display that continuation, but never
did, and instead left the old parts on display?

Thanks.