fn add_delta(prev_key: u64, delta: u64) -> Result<u64, CodecError>Expand description
Add a delta to the previous delta-encoded key.
Draft-19 Section 1.4.3: “The previous Type value plus the Delta Type MUST NOT be greater than 2^64 - 1. If a Delta Type is received that would be too large, the Session MUST be closed with a PROTOCOL_VIOLATION.” MoQT varints span the whole 64-bit range, so a peer can drive the sum past the end: a debug build panicked on the addition and a release build wrapped the key and reported the parameter under a type its sender never wrote.