bug#16797: 24.3.50; `emacs-lisp-mode' does not derive from `lisp-mode'

[Drew Adams]

This is as much a question as a bug report, but this seems a better
place to ask it than emacs-devel@gnu.org:

Why is `emacs-lisp-mode' derived from `prog-mode' and not `lisp-mode'?

To test whether, e.g., the current buffer is one where you could
evaluate a Lisp sexp in it, you would need to test whether the current
mode is derived from one or the other of these two Lisp modes.

Seems like `lisp-mode' should in some sense "encompass"
`emacs-lisp-mode', and perhaps any other Lisp modes as well.

Feel free to close this, if it does not in fact report a bug.
But in that case I would like to know what the reason is.

In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
 of 2014-02-11 on ODIEONE
Bzr revision: 116410 lekktu@gmail.com-20140211204823-l9l2s6tktfitq266
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/binary --enable-checking=yes,glyphs
 'CFLAGS=-O0 -g3' LDFLAGS=-Lc:/Devel/emacs/lib
 CPPFLAGS=-Ic:/Devel/emacs/include'