Default font (doc bug?)

[Stephen Berman]

How is the default font used by Emacs determined?  The only specific
reference I found in the manuals is in (emacs)Font X:

   The default font used by Emacs (under X) is:
        
        -adobe-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1

This is from my Emacs manual (in GNU Emacs 22.1.50.1
(i686-pc-linux-gnu, GTK+ Version 2.10.6) of 2007-04-30).  (The Elisp
manual, AFAICT, just makes reference to the default font without
either saying what it is or how it is chosen.)  But when I start Emacs
with -Q, the value of x-fixed-font-alist contains this:

   ("Font menu" 
    ("Misc" 
     ("Default" "-*-fixed-medium-r-*--16-*-*-*-*-*-fontset-16") 
     ...))

and the value of (frame-parameters) contains this:

   (font . "-*-fixed-medium-r-*--16-*-*-*-*-*-fontset-16")

I have emacs executables from previous builds, and those going back to
and including emacs-22.0.92 of 2007-01-22 show the same values as the
above with emacs -Q.  But in emacs-22.0.91 of 2006-12-16 the value of
x-fixed-font-alist contains this:

   ("Font menu" 
    ("Misc" 
     ("Default" "-Adobe-Courier-Medium-R-Normal--12-120-75-75-M-70-ISO8859-1")
     ...))

and the value of (frame-parameters) contains this:

   (font . "-Adobe-Courier-Medium-R-Normal--12-120-75-75-M-70-ISO8859-1")

This looks more in accord with the current Emacs manual, so is the
manual out of date?  And what, where, and when was the change that
changed the default font?  I couldn't find anything in the ChangeLogs
that referred to this, but I haven't been able to figure where the
default font comes from, so I probably overlooked it.  I note that all
the executables I have, including 22.0.91, have the same value of
standard-fontset-spec:

   "-*-fixed-medium-r-normal-*-16-*-*-*-*-*-fontset-standard,
        chinese-gb2312:-*-medium-r-normal-*-16-*-gb2312*-*,
        korean-ksc5601:-*-medium-r-normal-*-16-*-ksc5601*-*,
        chinese-cns11643-1:-*-medium-r-normal-*-16-*-cns11643*-1,
        chinese-cns11643-2:-*-medium-r-normal-*-16-*-cns11643*-2,
        chinese-cns11643-3:-*-medium-r-normal-*-16-*-cns11643*-3,
        chinese-cns11643-4:-*-medium-r-normal-*-16-*-cns11643*-4,
        chinese-cns11643-5:-*-medium-r-normal-*-16-*-cns11643*-5,
        chinese-cns11643-6:-*-medium-r-normal-*-16-*-cns11643*-6,
        chinese-cns11643-7:-*-medium-r-normal-*-16-*-cns11643*-7"

All executables were built under the same X server version, but
22.0.91 was built with GTK+ Version 2.8.10, whereas starting with
22.0.92 and up to my current build of 22.1.50, GTK+ is Version 2.10.6.
But presumably GTK+ is not responsible for the default font
difference, since I have also an executable of 22.0.90 built with the
Lucid toolkit and it shows the same font values as the GTK+ build of
22.0.91.

So how is the default font determined, and is there a doc bug in
(emacs)Font X?  Thanks,

Steve Berman