Steve Singer <ssinger(at)ca(dot)afilias(dot)info> writes:
> The man page for malloc on AIX is pretty clear on what happens when you
> try to malloc 0 bytes. It returns NULL.
Yes, that's a pretty common behavior for malloc(0). It should not cause
a problem here AFAICS.
... Oh, I see, the problem is that &labels[-1] might not compare to
&labels[0] the way we want. I think only the first hunk of your
patch is actually necessary.
regards, tom lane