decoder broken for all BUFR message edition 4 when section 1 length is 23

[vanh souvanlasy]

The decoder failing on all valid BUFR messages edition 4 where section 1 length is exactly 23 bytes, which correspond to specification.
The decoder seems to be expecting a padding bytes which is not always there. As a result, failed to decode several valid message.
which tested as OK using the BUFR checker.

[vanh souvanlasy (vanh-souvanlasy)]

This seems to affect the decoder since version 0.8.4

[Yves Pelletier (yves-pelletier)]

Vanh, thank you for the verbal briefing on this bug. My general comment would be that when decoding section 1, the value specified in octets 1-3 is the only "correct" value for the length of section 1. In a correctly encoded BUFR message, the total number of octets in section 1 must match the length given. A message that does not meet this condition is malformed and should trigger an error condition. And finally, there is no requirement for section 1 to be of even length.

[cpb (chris-beauregard)]

> And finally, there is no requirement for section 1 to be of even length.

Not in edition 4.

Regulation 94.1.3 (requiring that all sections are even length) still applies for edition 2 and 3.