I did not claim that source code constitutes an "invention" for the purpose of patent law or that the act of copying source code constitutes "making" an invention--the law is unclear on that. I was only stating that "selling" an invention was not the only act forbidden by patent law.
(a) Except as otherwise provided in this title, whoever without authority makes, uses, offers to sell, or sells any patented invention, within the United States or imports into the United States any patented invention during the term of the patent therefor, infringes the patent.
(b) Whoever actively induces infringement of a patent shall be liable as an infringer.
Title 35 of the U.S. Code is the full text of U.S. Patent legislation. Then there are the volumes of case law interpreting it, if you'd care to read it.
