Improve message for unknown untagged UIDNEXT response.

Per RFC3501 §6.3.1 and §6.3.2 ‘UIDNEXT’ must be returned in an OK
untagged response.  See also Appendix B#34.

However §6.3.1 suggests that it's in fact optional: “If this is missing,
the client can not make any assumptions about the next unique identifier
value.”

A correction was proposed in Errata ID 3445 https://www.rfc-editor.org/errata/eid3445 ,
and rejected on the ground that clients SHOULD support the implement
default behavior for missing data.

We heavily rely on the ‘UIDNEXT’ presence and won't implement a
workaround for its absence; instead we panic() with a more informative
message.

0 files changed, 0 insertions, 0 deletions