bug#17531: 24.4.50; REGRESSION: `cancel-debug-on-error' no longer works

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

> > Debugging was not cancelled for all functions, as it should have been.
> 
> Thanks.  I installed a fix for it in the emacs-24 branch.

But not in the trunk, perhaps?  Should we expect that it is fixed in
trunk also?

In any case, the regression is *still present* in this build, which
was created two days after your fix was installed in the emacs-24
branch.

If the fix was not applied to trunk, can you please do so?  If it was,
then please reopen the bug, as this is not fixed.

emacs -Q
M-x debug-on-entry forward-char
C-f
M-x cancel-debug-on-entry RET
C-f

Still enters the debugger.

FWIW, this regression is really quite annoying.  It pretty much
requires that one restart Emacs and get back into the proper setup
to continue.  Where one might typically toggle debugging of a
function multiple times while working on it, this effectively
puts a stop to that.

In GNU Emacs 24.4.50.1 (i686-pc-mingw32)
 of 2014-05-25 on ODIEONE
Bzr revision: 117153 tsdh@gnu.org-20140525174054-vzeh4zeg00a1ley8
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''