Thread: pgsql: Protect GIST logic that assumes penalty values can't be negative

Protect GIST logic that assumes penalty values can't be negative.

Apparently sane-looking penalty code might return small negative values,
for example because of roundoff error.  This will confuse places like
gistchoose().  Prevent problems by clamping negative penalty values to
zero.  (Just to be really sure, I also made it force NaNs to zero.)
Back-patch to all supported branches.

Alexander Korotkov

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/b26d8fda6535799be6eee1e93a8f11756b11af95

Modified Files
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doc/src/sgml/gist.sgml             |    2 ++
src/backend/access/gist/gistutil.c |   14 +++++++++++---
2 files changed, 13 insertions(+), 3 deletions(-)