Changes announced April 28, 2023

Stricter validation for json_name

v24 will forbid zero unicode code points (\u0000) in the json_name field option. Going forward, any valid Unicode characters will be accepted in json_name, except \u0000. \0 characters will still be allowed to be used as values.

Previously, the proto compiler allowed \0 characters in the json_name field option, but support for this was inconsistent across languages and implementations. To help prevent interoperability problems relating to mishandling of keys containing a \0 character, we are clarifying the spec to say that \0 is not allowed in json_name, and will be rejected by the compiler.