The fix in 6.2.12-1 for
HPCC-17403 does not appear to defend against a single record without a proper terminator. A user encountered the same error as in 17403, but with a non-zero-byte file. My analysis suggests it is due to lack of any valid record terminator (actual content was a header record with no terminator). I added only a terminator to that file and it sprayed correctly.
To test further, I created a four-record file with the final record lacking a terminator. The spray handled it without issue, so the problem appears to be isolated to the code that attempts to generate the header metadata in daftformat.cpp.
Error included here for clarity (line number change in daftformat.cpp):
assert((headerSize == 0) || (numInBuffer != bufferOffset)) failed - file: /mnt/disk1/jenkins/workspace/LN-Candidate-with-Plugins-6.2.12-1/LN/centos-6.0-x86_64/HPCC-Platform/dali/ft/daftformat.cpp, line 713