Eugene Chow <gene(at)paragonam(dot)com> writes:
> I believe this is a bug. The following function returns 'foo' instead
> of null:
NULLs in arrays aren't supported; the system interprets an attempt to
store a NULL into an array element as a no-op. Perhaps it should have
raised an error instead, but it's been that way for a long time and
we're not likely to change the behavior of existing releases.
(I'm actually right in the middle of adding support for null array
elements, but it won't appear until 8.2.)
regards, tom lane