[PD] packing anything in .33 can be dangerous

Krzysztof Czaja czaja at chopin.edu.pl
Wed Jun 20 11:27:21 CEST 2001

Hi all,

after bugfixing of pd_defaultlist() in Pd.33 this little snippet:

#X msg 100 50 foo bar;
#X obj 100 100 pack s;
#X obj 100 150 print;
#X connect 0 0 1 0;
#X connect 1 0 2 0;

loops forever (or rather, until it eats up all the memory...) due
to the cycling defaultlist/anymethod invocations.  In Pd.32 this
resulted in "symbol foo" printout.

Indeed, such a pack usage is strange (it is probably meant to be
unpack really) but is it illegal?  Max pack allows this.  The Max
printout gives simply "foo".

Perhaps the pack class should have a listmethod?  Or pack_anything()
should check if (x->x_n > 1)?  Or single argument packs should be
banned altogether?

Btw. the behaviour of abs, sin and other unary operators is also
affected, but without such a deadly consequences.  These objects
now simply refuse to operate on lists, while their previous
behaviour (compatible with Max) was to take the first list element,
as if preceded in a patch with an implicit $1 message.


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