bug#16306: 24.3.50; font change creates blank column on Lucid

[YAMAMOTO Mitsuharu]

>>>>> On Tue, 31 Dec 2013 10:05:33 +0200, Eli Zaretskii <eliz@gnu.org> said:

>> Date: Tue, 31 Dec 2013 11:27:36 +0900
>> From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
>> 
>> Steps to reproduce:
>> 
>> 1. $ emacs -Q &
>> 2. (set-frame-font "Courier-18") C-j
>> 
>> Then a blank column is created on the right edge of the frame (i.e.,
>> to the right of the right fringe).
>> 
>> I can reproduce it if Emacs is compiled with the Lucid widgets
>> support, but not for GTK+ or non-toolkit builds.

> Is the frame resized as result of changing the font, or do the frame
> dimensions stay fixed?

Resized.  Evaluation of (frame-pixel-width) gives different results
between Lucid and non-toolkit:

Lucid, showing blank column:
(list (frame-width) (frame-pixel-width)) => (80 674)
(set-frame-font "Courier-18")
(list (frame-width) (frame-pixel-width)) => (79 1162)

Non-toolkit, not showing blank column:
(list (frame-width) (frame-pixel-width)) => (80 674)
(set-frame-font "Courier-18")
(list (frame-width) (frame-pixel-width)) => (80 1166)

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