UPER decoded struct does not UPER encode

[gbaumgardner]

Generated from the SAEJ2735 2016 specification using the new v0.9.29 compiler. The code looks good and compiles, but I am having trouble with one of the types, MessageFrame. That type is new to J2735 2016 and is really a container frame for any other type. The code generated produces a CHOICE union called value, but it seems that encoding that type fails. I took a known UPER encoded set of bytes (00130b0000003781000000000005), and it seems to decode with uper_decode_complete just fine to the MessageFrame (see Decoding MessageFrame as SEQUENCE.txt and the XER encoding in MessageFrame.txt). However, that same structure was passed into the uper_encode_to_buffer, and it fails to encode. (see Encoding MessageFrame.txt). For comparison, I took a SPAT message based on the 2014 XML (removing unused elements), and was able to XER decode to the structure, which was then encoded as UPER, decoded back to a new structure, then encoded again with UPER. Everything worked fine for that structure (see SPAT 2016 Encode_Decode_Encode Test.txt) and the bytes looked identical and the XER output looked identical. I then, tried to do the exact same test using the XML tags around that same SPAT, and it SEG faults trying to XER decode.

Relavent debug output:
XER/SEQUENCE: tcv = 1, ph=0 [MessageFrame] (../src/r63/constr_SEQUENCE.c:711)
XER/SEQUENCE: tcv = 5, ph=1 [MessageFrame] (../src/r63/constr_SEQUENCE.c:711)
XER/SEQUENCE: tcv=5, ph=1, edx=0 (../src/r63/constr_SEQUENCE.c:770)
INTEGER body 2 0x31..0x39 (../src/r63/INTEGER.c:343)
Freeing INTEGER as a primitive type (../src/r63/asn_codecs_prim.c:125)
XER/SEQUENCE phase => 1, step => 1 (../src/r63/constr_SEQUENCE.c:685)
XER/SEQUENCE: tcv = 5, ph=1 [MessageFrame] (../src/r63/constr_SEQUENCE.c:711)
XER/SEQUENCE: tcv=5, ph=1, edx=1 (../src/r63/constr_SEQUENCE.c:770)

Relavent stack trace
#0 0x0000000000000000 in ?? ()
#1 0x00007ffff74deb6e in SEQUENCE_decode_xer (opt_codec_ctx=0x7fffffffda60, td=0x7342c0 <asn_DEF_MessageFrame>, struct_ptr=0x7fffffffdab8, opt_mname=0x0, buf_ptr=0x7377bf, size=1754)
at ../src/r63/constr_SEQUENCE.c:676
#2 0x00007ffff74971eb in xer_decode (opt_codec_ctx=0x7fffffffda60, td=0x7342c0 <asn_DEF_MessageFrame>, struct_ptr=0x7fffffffdab8, buffer=0x737798, size=1793) at ../src/r63/xer_decoder.c:37

Note that DER encoding/decoding seems to work great for the MessageFrame, so the problem seems to be UPER and XER related. And it seems to be specific to MessageFrame.

SPAT 2016 Encode_Decode_Encode Test.txt
Encoding MessageFrame.txt
MessageFrame.txt
Decoding MessageFrame as SEQUENCE.txt

[vlm]

Fixed. Check it out (in examples/sample.source.J2735):

./j2735-dump -ixer -oper sample-MessageFrame-1.xer | ./j2735-dump -iper -oxer -

or just

make check