MetadataResponse error code handling

Hi folks,

I was wondering in which cases the PartitionMetadata section of a
MetadataResponse [1] can contain useful information?

I had been working under the assumption that when the PartitionErrorCode
was 0 (NoError) then the rest of the data would be legitimate, and that
when the error was non-0 then the rest of the data would be blank/empty/etc.

However, I recently discovered a JIRA ticket [2] which suggests otherwise,
namely that there are certain error codes for which parts of the remainder
of the metadata may still be filled in. I have not found any explicit
documentation for which error codes this is true. Does anybody know?

Thanks,
Evan

P.S. I'm not 100% sure if this kind of question should go on users@ or dev@.
Please let me know if I'm in the wrong place.

[1]
https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-MetadataResponse
[2] https://issues.apache.org/jira/browse/KAFKA-1609