bug#12345: 24.2.50; doc string of `text-scale-adjust'

[Bastien]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> I enhanced the docstring and rewrote the command so that it does
>> not use a temporary keymap.
>
> Not using a temporary keymap means reverting to the old code: please
> explain precisely why using a temporary keymap is a problem (there are
> good reasons to use it: e.g. it makes key-translation-map and friends
> work correctly).

The `read-event' loop allows to keep the message displayed 
(see the FIXME).

But I hit something weird.

from emacs -q, try to edebug-defun `text-scale-adjust', 
then use `C-x C-+', then `c' in the debug loop, then quit.

The temporary keymap is not temporary anymore, and the `-'
and `+' keys are still bounded to `text-scale-adjust'.

Surely something weird when `set-temporary-overlay-map' is 
called from within a debug loop?

-- 
 Bastien