bug#19721: 25.0.50; Mode-line not redrawn with expose events

[YAMAMOTO Mitsuharu]

>>>>> On Sat, 31 Jan 2015 12:53:37 +0200, Eli Zaretskii <eliz@gnu.org> said:

> Does the patch below fix the problem?

> I cannot reproduce your recipe on the systems to which I have access,
> so I used a slightly modified procedure and the dump-glyph-matrix
> function to show what I think is the same issue: namely, in a frame
> with 3 vertically-arranged windows, the window "after the selected
> one" (in the next-window sense) has its mode-line row disabled in the
> current glyph matrix.  That problem is solved by the patch below, but
> I'm not sure it solves yours.

With this patch, the mode-lines are redrawn when they are exposed.
But I also observe that a mode-line part is not updated with the last
C-x o (see the 3rd mode-line in the screenshot) with the previously
mentioned procedure on the Mac port.  Strangely, if I try C-x o three
times further, then the second mode-line part is also not updated.
Unfortunately, I couldn't reproduce it with Cent OS 5.11.

                                     YAMAMOTO Mitsuharu
                                mituharu@math.s.chiba-u.ac.jp