bottomhandler == NULL

[John (_You_ hide, they seek.) Mackin <john@civil.su.oz.au>]

I don't know exactly what's going on here, but I've tracked it down a
bit.  Shouldn't bottomhandler always be non-NULL?  Anyway, if you
try this one:

; prompt = (three element list) es

You get this one:

except.c:26: assertion failed (handler != NULL)
illegal instruction--core dumped

What's happened is that prim_setprompt tries to throw an error because
it thinks prompt should only have two elements, and the first throw
(back to vardef) works OK, but in the course of doing that the
handler->up is NULL, so bottomhandler gets assigned NULL and when
vardef tries to re-throw the exception the assertion fails.

Apart from the bug, couldn't we just have extra elements of
prompt silently ignored, like in rc?  I find it handy to carry
a third one around.

OK,
John.