getrandom-nonblocking-v2.patch:

+		/* Alternative might be to return all-zeroes as a strong
+		 * signal that these are not random data. */

I don't understand why you propose that in a comment of your change. I don't recall that this idea was proposed or discussed here.

IMHO it's a very bad idea to fill the buffer with zeros, the caller simply has no idea how to check the quality of the entropy. A buffer filled with zeros is "possible" even with high quality RNG, but it's really very very rare :-)

If you consider that a strong signal is required, you must raise an exception. But it looks like users don't care of the quality of the RNG, they request that Python "just works".