[PROTON-2517] The new C codec can misinterpret pn_data_t values resulting in unintended wire data.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-c-0.37.0
• Fix Version/s: proton-c-0.37.0
• Component/s: proton-c
• Assignee: Clifford Jansen
• Reporter: Clifford Jansen
• Created: 14/Mar/22 14:04
• Updated: 07/Apr/22 17:01
• Resolved: 15/Mar/22 17:29

Description

See the C++ frame trace from

  https://issues.redhat.com/browse/ENTMQCL-3278

The zero length array is printed instead of a null because the test in emit_multiple() from emitters.h fails to set the current node of the pn_data_t to the first node.  The test

  if (pn_data_type(data) == PN_ARRAY) { //...

fails and the array processing logic is bypassed, including the lines

     switch (pn_data_get_array(data)) {
        case 0:
          pni_emitter_writef8(emitter, PNE_NULL);