[PD-dev] [pure-data:patches] #555 never send NULL selectors to objects

[IOhannes m zmoelnig]

On 2015-09-10 01:01, Miller Puckette wrote:
> I'm not sure this is a real problem - _anything and _list methods simply aren't guaranteed
> anything about the "s" argument - it shouldn't ever be dereferenced.

oha.

#1 why do we have the "s" argument in the first place?
#2 shouldn't there be a huge blinking sign in m_pd.h that warns against
it's use?

#3 i see that the "s" argument (to the _anything method) is *used* in
Pd-code, though hardly ever dereferenced (notable exception being
print_anything()) - am i just nitpicking?


in any case:
the problem really was found from a crasher-bug triggered by zexy's
[relay] object. (and object similar to [route] but without stripping the
selector).
[relay] doesn't do any dereferencing of the "s" argument.
however, it passes the "s" argument on to outlet_anything(), which will
then crash Pd's message dispatcher.


so to revert the question: is the Pd-dispatcher 'guaranteed anything
about the "s" argument' in the outlet_list() and outlet_anything() methods?

if not, then the 0002-gracefully-handle-messages-with-NIL-selector.patch
(attached to the ticket) will fix it (however, it doesn't fix the buggy
[print] object that dereferences the "s" argument in its _anything() method.

fgmasdr
IOhannes