Is the implementation of DPSsetgstate: in GSContext correct?

[Banlu Kemiyatorn]

It saids,

"setgstate gstate setgstate - LEVEL 2

replaces the current graphics state by the value of the gstate object. 
This is a copying operation, so subsequent modifications to the value of 
gstate will not affect the current graphics state or vice versa. Note 
that this is a wholesale replacement of all components of the graphics 
state; in particular, the current clipping path is replaced by the value 
in gstate , not intersected with it. "

So I wonder if it is the right thing that DPSsetgstate: ctxt_pop the 
value into current gstate
without copying.

id aState;
ctxt_pop(aState...
gstate = [aState copy];
RETAIN(gstate);

solved my problem. But I am not really sure with these.
id