[issue46508] codec name acceptance became way too lenient in 3.9

Gregory P. Smith added the comment: while figuring this issue out, it may also make sense to address https://bugs.python.org/issue44723 as well. -- ___ Python tracker ___ ___

[issue46508] codec name acceptance became way too lenient in 3.9

New submission from Gregory P. Smith : in 3.8 this was not a valid codec name: "เ_เ_เ_iDnA" in 3.9 it gets treated as idna and triggers the punycode decoder when passed to bytes.decode(codec). Discovered by oss-fuzz. _Likely_ a consequence of https://bugs.python.org/issue37751 The consequence