"Attempt to modify read-only object" error with set-frame-configuration

[martin rudalics <rudalics@gmx.at>]

With Emacs -Q evaluating the form

(let ((cfg (current-frame-configuration)))
   (set-frame-configuration cfg))

I am told

Debugger entered--Lisp error: (error "Attempt to modify read-only object")
   modify-frame-parameters(#<frame EMACS@MACHNO 0x1ae2400> ((parent-id) (explicit-name) (display . "") (icon-name) (window-id . "2224") (top . 100) (left . 100) (buried-buffer-list) (buffer-list #<buffer *scratch*>) (unsplittable) (modeline 
. t) (width . 80) (height . 42) (environment) (background-mode . light) (display-type . color) (right-fringe . 10) (left-fringe . 10) (right-fringe) (left-fringe) (horizontal-scroll-bars . t) (window-system . w32) (visibility . t) 
(scroll-bar-width . 20) (cursor-type . box) (auto-lower) (auto-raise) (icon-type) (title) (buffer-predicate) (tool-bar-lines . 2) (menu-bar-lines . 1) (right-fringe) (left-fringe) (line-spacing) (screen-gamma) (border-color . "black") 
(cursor-color . "black") (mouse-color . "black") (background-color . "SystemWindow") (foreground-color . "SystemWindowText") (vertical-scroll-bars . right) (internal-border-width . 0) (border-width . 2) (font . "-outline-Courier 
New-normal-r-normal-normal-16-96-120-120-c-*-iso8859-1")))
   set-frame-configuration((frame-configuration (#<frame EMACS@MACHNO 0x1ae2400> (... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 
... ... ... ... ... ...) #<window-configuration>)))
   (let ((cfg ...)) (set-frame-configuration cfg))
   eval((let ((cfg ...)) (set-frame-configuration cfg)))
   eval-last-sexp-1(nil)
   eval-last-sexp(nil)
   call-interactively(eval-last-sexp)

Can anyone reproduce that?


In GNU Emacs 23.0.50.1 (i386-mingw-windows98.3000)
  of 2007-12-04 on MACHNO
Windowing system distributor `Microsoft Corp.', version 4.90.3000
configured using `configure --with-gcc (3.4)'

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: dea
   locale-coding-system: cp1252
   default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
   tooltip-mode: t
   tool-bar-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   unify-8859-on-encoding-mode: t
   utf-translate-cjk-mode: t
   auto-compression-mode: t
   line-number-mode: t