I'm reading some of the fallout from Redis relicensing their software to be non-Free, and I say this:
I will never, ever sign a Contributor License Agreement before submitting a patch to any project[0]. They exist so that projects can relicense my contributions later, perhaps in ways I don't agree with. I retain my copyright, TYVM, and if you want to turn my GPLed patch into a proprietary license, better start re-writing.
[0] I sign one for the FSF once. They’re not gonna rugpull like that.