Initialize padding bytes in btree_gist varbit support.
The code expands a varbit gist leaf key to a node key by copying the bit
data twice in a varlen datum, as both the lower and upper key. The lower key
was expanded to INTALIGN size, but the padding bytes were not initialized.
That's a problem because when the lower/upper keys are compared, the padding
bytes are used compared too, when the values are otherwise equal. That could
lead to incorrect query results.
REINDEX is advised for any btree_gist indexes on bit or bit varying data
type, to fix any garbage padding bytes on disk.
Per Valgrind, reported by Andres Freund. Backpatch to all supported
versions.
Branch
------
REL9_3_STABLE
Details
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http://git.postgresql.org/pg/commitdiff/d5b912c905efd531a6228d08c98cd92d49cdd94c
Modified Files
--------------
contrib/btree_gist/btree_bit.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)