Code execution via aperture macro integer overflow

Integer overflow in Gerbv 2.7.0 and development commits b5f1eacd and 71493260 allows attackers to execute code via a crafted Gerber file. The simplify_aperture_macro function calculates an outline parameter count in a signed integer, permits the multiplication to wrap negative, and passes the resulting size to memcpy, which writes beyond a fixed parameter array. Exploitation requires Gerbv or a consuming application to process the attacker-controlled file and executes code with that process's privileges.