That seems pointless, because then patches could not be distributed. Seldom are patches economically viable for exactly one person to create, one at a time, fo

That seems pointless, because then patches could not be distributed. Seldom are patches economically viable for exactly one person to create, one at a time, for themselves. That's the same burden of being a proprietary software company without any potential upside. Maybe for an organization, and in those cases a source-code escrow is not unheard of. But really it's just a lifeboat so you can move on gracefully.