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| author | Igor Babaev <igor@askmonty.org> | 2019-02-24 02:02:07 -0800 |
|---|---|---|
| committer | Igor Babaev <igor@askmonty.org> | 2019-02-24 02:02:07 -0800 |
| commit | 25870f48cf66c5984332120d1cb11db79ca1b5f6 (patch) | |
| tree | ed38ba3e60266d5cdc4cdd37676154137c7b9cc6 | |
| parent | 31deef0953a5cf7259e1d064ae7f2e0dde922436 (diff) | |
| download | mariadb-git-25870f48cf66c5984332120d1cb11db79ca1b5f6.tar.gz | |
MDEV-18668 Server crash or ASAN use-after-poison in Item_equal_iterator /
st_select_lex::pushdown_from_having_into_where upon query
with impossible WHERE condition
Do not push from HAVING into impossible WHERE
| -rw-r--r-- | mysql-test/main/having_cond_pushdown.result | 12 | ||||
| -rw-r--r-- | mysql-test/main/having_cond_pushdown.test | 13 | ||||
| -rw-r--r-- | sql/sql_select.cc | 6 |
3 files changed, 30 insertions, 1 deletions
diff --git a/mysql-test/main/having_cond_pushdown.result b/mysql-test/main/having_cond_pushdown.result index 9d2fbcead4e..ef7368bd1fb 100644 --- a/mysql-test/main/having_cond_pushdown.result +++ b/mysql-test/main/having_cond_pushdown.result @@ -1906,3 +1906,15 @@ EXPLAIN DROP TABLE t1,t2; DROP VIEW v1; DROP FUNCTION f1; +# +# MDEV-18668: pushdown from HAVING into impossible WHERE +# +CREATE TABLE t1 (a INT, b INT); +INSERT INTO t1 VALUES (1,1),(2,2); +SELECT a FROM t1 WHERE b = 1 AND b = 2 GROUP BY a HAVING a <= 3; +a +EXPLAIN +SELECT a FROM t1 WHERE b = 1 AND b = 2 GROUP BY a HAVING a <= 3; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE +DROP TABLE t1; diff --git a/mysql-test/main/having_cond_pushdown.test b/mysql-test/main/having_cond_pushdown.test index 2af9d58bc4d..2fbb5708c50 100644 --- a/mysql-test/main/having_cond_pushdown.test +++ b/mysql-test/main/having_cond_pushdown.test @@ -473,3 +473,16 @@ eval $no_pushdown explain format=json $query; DROP TABLE t1,t2; DROP VIEW v1; DROP FUNCTION f1; + +--echo # +--echo # MDEV-18668: pushdown from HAVING into impossible WHERE +--echo # + +CREATE TABLE t1 (a INT, b INT); +INSERT INTO t1 VALUES (1,1),(2,2); + +SELECT a FROM t1 WHERE b = 1 AND b = 2 GROUP BY a HAVING a <= 3; +EXPLAIN +SELECT a FROM t1 WHERE b = 1 AND b = 2 GROUP BY a HAVING a <= 3; + +DROP TABLE t1; diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 5faadb1dded..4f98153d752 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1929,8 +1929,11 @@ JOIN::optimize_inner() DBUG_RETURN(1); } + /* Do not push into WHERE from HAVING if cond_value == Item::COND_FALSE */ + if (thd->lex->sql_command == SQLCOM_SELECT && - optimizer_flag(thd, OPTIMIZER_SWITCH_COND_PUSHDOWN_FROM_HAVING)) + optimizer_flag(thd, OPTIMIZER_SWITCH_COND_PUSHDOWN_FROM_HAVING) && + cond_value != Item::COND_FALSE) { having= select_lex->pushdown_from_having_into_where(thd, having); @@ -15380,6 +15383,7 @@ Item *eliminate_item_equal(THD *thd, COND *cond, COND_EQUAL *upper_levels, @param cond condition to process @param cond_equal multiple equalities to take into consideration @param table_join_idx index to tables determining field preference + @param do_substitution if false: do not do any field substitution @note At the first glance full sort of fields in multiple equality |