Suppose I start a GPLv3 licensed project.
I take care of pasting all the license text is in the LICENSE.txt and set up a reference to it on top of every source file.
I do not exhibit any CONTRIBUTING.txt or a Contributor License Agreement (CLA) in any form.
I merge a few large pull requests
Now I want to double-license the code (take my project's GPLv3 code and sell it under a commercial license while keeping it under GPLv3 for non-customers)
Am I breaking GPLv3?
I thought so, but when you read the paragraph 11 of GPLv3 it says:
Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.
This looks an awful lot like a CLA embedded in the license.
Does this mean I can double-license? Or do I need all contributors' permission?
EDIT Very clear, thanks everyone! FYI I have decided to rewrite my project from scratch in another language because I can't get the contributors to sign anything.