RE: master aae9ac2: Avoid an infloop in shr when filling text with :align-to properties

[Drew Adams]

>>> I  was pretty sure I was using the `e' command, but perhaps
>>> muscle memory made me use `M-:' instead?
>> That would be my guess: it happens to me all the time.
> 
> This must be a common mistake.
> Should the debugger rebind M-: to be like e?

If you mean rebind `M-:' to do what `e' does then
no, definitely not, IMO.  Users need to be able to
use _both_ `e' and `M-:' in the debugger buffer,
to get their different behaviors.

> Make it ask for confirmation?

Dunno whether you mean `e' or `M-:' (in debugger),
but I'd again say no.  It's perfectly normal to use
both `M-:' and `e' in the debugger, for different
purposes.  I don't see why either should ask for
confirmation.

When you use `e' we already use a prompt that should
make it clear that `e' is being used (provided you
read the prompt):

  Eval in stack frame:

If we think that's not obvious/clear enough, perhaps
adding some flash (color? ding? mode-line indicator?)
would help.

That might not help if someone uses `M-:' by mistake,
but if a user gets used to expecting it for `e' then
its lack might be noticeable enough.

Another possibility is to change the prompt for `M-:'
when in the debugger, to make it clear that the eval
takes place in the outside-debugger context, not in
the debugger stack frame.  But that introduces a
different prompt for `M-:' depending on the context,
which is maybe not so good.

Do I think this is really a problem that needs
fixing?  No.  But those are suggestions that occur
to me, in case others think it is.