bug#16677: 24.3.50; Wrong type argument: char-or-string-p, 67108923

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

emacs -Q

C-q C-;

Gives the cited error message.  It should give a more user
interface-level error, saying something to the effect that the key
sequence you used does not correspond to a character.

Note: in Emacs 20, this just inserts the escape character (^[), which is
wrong.  In Emacs 22, it just inserts the semicolon character (;), which
is also wrong.

Emacs 23 got it right, but it did not make the extra effort to give the
user an error message that s?he deserves: something more helpful than a
low-level barf message (even if that message might be comprehensible to
a knowledgable Emacs user).

Emacs can do better than that - this is, after all, a command, i.e.,
something that users use directly.

(I discovered this by accident, when my fingers slipped.)

In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
 of 2014-02-02 on ODIEONE
Bzr revision: 116242 rudalics@gmx.at-20140202130041-n967dw77nw7ztvy9
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'