bug#12149: 24.1; `C-h f' is worse and worse at telling where a function was defined

[Drew Adams]

I have this code:
 
(defun 1on1-setup-minibuffer-frame-coloring ()
  "Redefine some built-in functions so they color the minibuffer frame.
Functions redefined: `y-or-n-p', `top-level', `abort-recursive-exit'."
 
  (or (fboundp '1on1-ORIG-y-or-n-p)
      (fset '1on1-ORIG-y-or-n-p (symbol-function 'y-or-n-p)))
 
  (defun y-or-n-p (prompt)
    "Ask user a \"y or n\" question.  Return t if answer is \"y\".
Takes one argument, which is the string to display to ask the question.
It should end in a space; `y-or-n-p' adds `(y or n) ' to it.
No confirmation of answer is requested; a single character is enough.
Also accepts SPC to mean yes, or DEL to mean no."
    (if (> (minibuffer-depth) 0)
        (1on1-ORIG-y-or-n-p prompt)
      (1on1-color-minibuffer-frame-on-setup)
      (prog1 (1on1-ORIG-y-or-n-p prompt)
        (1on1-color-minibuffer-frame-on-exit))))
 

  (or (fboundp '1on1-ORIG-top-level)
      (fset '1on1-ORIG-top-level (symbol-function 'top-level)))
 
  (defun top-level ()
    "Exit all recursive editing levels."
    (interactive)
    (1on1-color-minibuffer-frame-on-exit)
    (1on1-ORIG-top-level))
 
...)
 
In Emacs prior to Emacs 23, `C-h f' did not point to the wrong files
as having defined these function.  At least it did not lie and steer
you wrong.
 
Emacs 23.4 did not point to the wrong file for `y-or-n-p', but it did
point to the wrong file for `top-level'.
 
Emacs 24.1 gets them both wrong.  It simply gives the original location
(from emacs -Q) for each of them: `C source code' for `top-level' and
`subr.el' for `y-or-n-p'.  This is not good.  Better to say "no idea"
than to mislead the user this way.
 
Instead of improving locating function definitions, things have gotten
worse.
 

In GNU Emacs 24.1.1 (i386-mingw-nt5.1.2600)
 of 2012-06-10 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include'