[RFA]: Fix crashing bug in set follow-fork-mode

[Andrew Cagney]

"Daniel Berlin+list.gdb-patches" wrote:
> 
> Andrew Cagney <ac131313@cygnus.com> writes:
> 
> I have a better idea.
> 
> I just made it check the enum list, when the command is added, like
> so:

That, separatly, may not hurt (it's up to Fernando).  I'm not sure about
the ``isalphanum()'' I wonder what happens when it gets
internationalized and the check works in part by good luck.  Personally,
I'd like to see a simpler interface.

The testsuite should still be checking that the commands it expects are
there.  Otherwize  (as we've done once or twice ....) we  run the risk
of loosing commands / changing interfaces between releases :-(

	enjoy,
		Andrew