bug#17983: 24.4.50; digit keys in *Messages* unhelpful, hang Emacs, etc.

[Drew Adams]

emacs -Q

C-x b *Messages*

C-h k 7

Tells you that 7 is bound to `digit-argument'.

Why?  It should NOT be.  It is useful to be able to write text in
*Messages*, e.g., to set off or group sets of debug messages.  There is
no need for digit N to be a short cut for C-u N in buffer *Messages*.

C-x C-q ; Make the buffer writable

Unfortunately, Emacs has recently screwed *Messages* so that most keys
are not self-inserting.  This was misguided.  Be that as it may...

C-q H C-q e C-q l C-q p C-q !

Painful, but OK so far.  Now try this:

C-q 7

Nothing.  Nada.

C-q 7 C-q 7 C-q 7.  You see ^G inserted each time (except the first)
that you hit C-q (not when you hit 7), because 7 acts as a prefix arg
for the following ^Q.  Wunderbar.  A feature, no doubt.

C-q 7 7 7.  Now Emacs is hosed - in Neverneverland.  ESC ESC ESC no
good; C-g no good.  No mouse, no keys, nada.  And no CPU use.  Just
hosed.

The only recourse is to kill the Emacs task from the Windows Task
Manager.

OK, you might not see this freezing behavior each time.  Sometimes C-g
does quit OK, as does C-b, muose-1 etc.  Hit C-q and then hold 7 down
for a few seconds, then C-g.  If Emacs is not frozen solid and C-g works
then you get helpful feedback such as this:

Quit
user-error: A-C-H-M-S-s- is not a valid character

Other times, Emacs freezes solid.  Regardless of whether it freezes each
time, if you hit C-q and then 7 one or more times there is no feedback -
already a no-no (bug).

C-q should simply quote the 7, as it should quote other characters you
type (including ^U, BTW).

Trying to "improve" *Messages* for Emacs 24 was misguided.  It is far
less useful now than it was before.  Is there even one change that was
made that represents progress - something useful?  Please consider
reverting it to what it was since Day One.  Barring that requested
return to sanity, please at least fix the C-q behavior.  Thx.


In GNU Emacs 24.4.50.1 (i686-pc-mingw32)
 of 2014-06-28 on ODIEONE
Bzr revision: 117431 rgm@gnu.org-20140628015517-eku6hj8mpgcvfnso
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/snapshot/trunk
 --enable-checking=yes,glyphs 'CFLAGS=-O0 -g3'
 LDFLAGS=-Lc:/Devel/emacs/lib 'CPPFLAGS=-DGC_MCHECK=1
 -Ic:/Devel/emacs/include''