Subject: Re: bug#19972: 24.4; Font size change doesn't update (window-total-width)

From: martin rudalics <[email-masked]>
Date: Sun, 01 Mar 2015 16:54:26 +0100

> For the purposes of this discussion, I think the only thing that
 > matters is that it applies the change in the default face's font.

If `set-frame-font' were involved, then it has a `keep-size' argument
which, when set, should keep the frame's pixel size constant.  But I
nowhere see `set-frame-font' getting called with that argument non-nil.

 >> Anyway.  Why do you think that `window-total-width' should return 192 in
 >> the first call?  In principle, face/font changes are supposed to keep
 >> the number of columns/lines unchanged so returning 240 seems reasonable
 >> to me.
 >
 > Indeed.  It does for me.  Could this be something specific to GTK or
 > the window manager?

I tried with Gtk and the numbers of lines/columns remain unaltered.  On
Windows I lose one line because the tool bar gets larger by one pixel.

 > Also, I don't understand why the initial value is 240 in the first
 > place.  By default, "emacs -Q" creates a 80-column window, so I'd
 > expect window-total-width to return a value slightly larger than 80 (I
 > get 84 here).
 >
 > So it sounds like some additional factors are at work here.

Indeed.  This issue needs clarification too.

martin