schema_registry_encode truncation of input json before encode

[hendoxc]

I previously posted an issue with schema_registry_encode that was resolved by fixing a race condition

I'm getting similar issues with, but an extra key is now truncated:

{"key_1":  1, "key_2": {"sub_key_1": 2}, "key_3": 3}

would result in an error message like

could not decode any json data in input {"sub_key_1": 2}, "key_3": 3} for key "key_2"

[mihaitodor]

Hey @hendoxc, I had a quick look at this, but I can't come up with a way to reproduce it. Are you able to trigger it consistently and is it possible to come up with a setup that I can run myself?