So basically, I'm using object.smash(true) to break a block but leave no item behind (in this case its because i'm spawning it manually with some contextual changes, but that's irelivant). It was working fine up untill 1.2. Until i started getting complaints that items were leaving two copies behind one modified, and one unmodified. i've looked over everything i can and none of it makes sense. its just simply not working as the documentation states. i get the same result weather or not i use true or false by the way.
Had a similar issue. A workaround is "smashOnBreak" : true in the .object file and spawning the item in the die() function with any relevant adjusted parameters.