dnsimple / dns_erlang / 30147162684

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Build Type

push

github

Committed by web-flow

Commit Message

Fix premature OPT RR and additional-section dropping near max_size (#137)

encode_message_default sized the OPT RR and trailing additional records
against SpaceLeft1 + PreservedOptRRBinSize - BodySize. SpaceLeft1 had
already subtracted the question-section size, but Body (the accumulator
returned by encode_message_d_req) starts from the question bytes, so
BodySize subtracts them again. The pool for the OPT RR and additional
records was therefore short by the question-section size, and both were
dropped from responses within that many bytes of max_size even though
they fit. For EDNS responses that meant omitting the OPT RR (contra
RFC 6891) while still returning an untruncated answer: a 493-byte
response under a 512-byte limit lost its 11-byte OPT RR.

Size the pool from SpaceLeft0 instead, which subtracts the question
bytes exactly once via BodySize. The truncated branch already accounted
this way (SpaceForOptRR = MaxSize - header - questions).

Coverage Stats

1 of 1 new or added line in 1 file covered. (100.0%)

2 existing lines in 1 file now uncovered.

2791 of 3152 relevant lines covered (88.55%)

10912.8 hits per line