pgsql: Fix bugs in contrib/pg_trgm's LIKE pattern analysis code.

Fix bugs in contrib/pg_trgm's LIKE pattern analysis code.

Extraction of trigrams did not process LIKE escape sequences properly,
leading to possible misidentification of trigrams near escapes, resulting
in incorrect index search results.

Fujii Masao

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/b2a01b9ad1c6b074df1c4bc75ca988230dfa3cf0

Modified Files
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contrib/pg_trgm/expected/pg_trgm.out | 12 +++++++++
contrib/pg_trgm/sql/pg_trgm.sql | 2 +
contrib/pg_trgm/trgm_op.c | 44 +++++++++++++++++++--------------
3 files changed, 39 insertions(+), 19 deletions(-)