RE: columns displayed on one line in frame / window

["Drew Adams" <drew.adams@oracle.com>]

> I have emacs 21.3.1 running on XP SP3.  When I evaluate the
> expression using M-: (Meta-colon), (frame-width) 
> it returns 72.  However, if I look at the number of columns I
> can display before the line wraps, it's actually 80.

Are you sure? Go to the character that you think is in column 80 and hit `C-x
='. Does it say that the char is at column 80?

If so, and assuming that the characters in question are of the default size for
the frame, then please report a bug. However, bugs are no longer being fixed in
Emacs 21, so you might want to upgrade to Emacs 22.3 and check that the same
problem exists. Most helpful of all would be to install the Emacs 23 pretest and
check that.

> Isn't frame-width supposed to be the same as the number of
> columns that can fit on one line?  (I'm using a fixed-width font

Yes. But the actual displayed width of a frame can include such things as the
fringe, a scroll bar, and frame borders. The available area for text display
should, though, be `frame-width' characters wide. If it is not, something is
wrong.

Which characters? Characters of fixed width and of the `default' face for the
frame in question.
	 
> Likewise, if I set the frame width with
> (set-frame-width (selected-frame) 72)
> it sets up the window so that 80 columns fit on one line.  What gives?

Sounds like a bug. When you report it, be sure to give a clear recipe that
starts with `emacs -q --no-site-file'. That is, do not test only using your
.emacs.