So the question is only whether +0 or -0 (or +0, etc.) should be
accepted as integers by FILTER_VALIDATE_INT. I think they should,
because
we also accept non-canonical inputs such as +5, i.e., we always
accept a
sign. It's true that 0 is neither positive or negative, but I don't
think
Both statements are wrong, since the purpose of the filter extension
is to validate strings. I found this information in BR #52884 (see
last comment). Maybe it should be added to the docs? It's nonsense to
say, that FILTER_VALIDATE_INT must work like var_dump() since they
are both serving
