You can't sue FOSS authors for infringing patents (source code) -- you can only sue the distributors of executable implementations (binaries)
The text of an ideal software patent is (or has a direct mapping to) the source code of an implementation, just as an ideal steam engine patent would be blueprints and schematics. The text of patents must always be publicly available to be enforceable -- it's the whole point, absolutely central to "the promotion of the useful arts and sciences".
You license the production of artifacts, not the spread of ideas.
If I supply you with tailored parts necessary to perform/make a patented invention then that's contributory infringement.
In the US Findlaw says:
"Contributory infringement occurs when a party supplies a direct infringer with a part that has no substantial non-infringing use. Literal infringement exists if there is a direct correspondence between the words in the patent claims and the infringing device."
You could argue that the source code is an implementation.
Anyway the point is rather irrelevent, you aren't going to sue anonymous contributer100. You are going to sue, or threaten to sue, companies who propose using opensource platforms for their new website rather than buying from one of your members.
The text of an ideal software patent is (or has a direct mapping to) the source code of an implementation, just as an ideal steam engine patent would be blueprints and schematics. The text of patents must always be publicly available to be enforceable -- it's the whole point, absolutely central to "the promotion of the useful arts and sciences".
You license the production of artifacts, not the spread of ideas.