Fix corner case with PGP decompression in pgcrypto
A compressed stream may end with an empty packet, and PGP decompression
finished before reading this empty packet in the remaining stream. This
caused a failure in pgcrypto, handling this case as corrupted data.
This commit makes sure to consume such extra data, avoiding a failure
when decompression the entire stream. This corner case was reproducible
with a data length of 16kB, and existed since its introduction in
e94dd6a. A cheap regression test is added to cover this case.
Thanks to Jeff Janes for the extra investigation.
Reported-by: Frank Gagnepain
Author: Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/16476-692ef7b84e5fb893@postgresql.org
Backpatch-through: 9.5
Branch
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REL_13_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/35e142202b14fa12f8edbd7e58b33c39d3c03c62
Modified Files
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contrib/pgcrypto/expected/pgp-compression.out | 30 +++++++++++++++++++++++++++
contrib/pgcrypto/pgp-compress.c | 22 ++++++++++----------
contrib/pgcrypto/sql/pgp-compression.sql | 21 +++++++++++++++++++
3 files changed, 62 insertions(+), 11 deletions(-)