diff options
| -rw-r--r-- | mysql-test/r/range.result | 9 | ||||
| -rw-r--r-- | mysql-test/t/range.test | 10 | ||||
| -rw-r--r-- | sql/opt_range.cc | 11 |
3 files changed, 30 insertions, 0 deletions
diff --git a/mysql-test/r/range.result b/mysql-test/r/range.result index cc5e8d2be96..69ae81982a9 100644 --- a/mysql-test/r/range.result +++ b/mysql-test/r/range.result @@ -1219,3 +1219,12 @@ explain select * from t2 where a=1000 and b<11; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 5 const 502 Using where drop table t1, t2; +# +# Bug #47123: Endless 100% CPU loop with STRAIGHT_JOIN +# +CREATE TABLE t1(a INT, KEY(a)); +INSERT INTO t1 VALUES (1), (NULL); +SELECT * FROM t1 WHERE a <> NULL and (a <> NULL or a <= NULL); +a +DROP TABLE t1; +# End of 5.1 tests diff --git a/mysql-test/t/range.test b/mysql-test/t/range.test index e1411e7fd46..7b35f69c041 100644 --- a/mysql-test/t/range.test +++ b/mysql-test/t/range.test @@ -1046,3 +1046,13 @@ explain select * from t2 where a=1000 and b<11; drop table t1, t2; +--echo # +--echo # Bug #47123: Endless 100% CPU loop with STRAIGHT_JOIN +--echo # + +CREATE TABLE t1(a INT, KEY(a)); +INSERT INTO t1 VALUES (1), (NULL); +SELECT * FROM t1 WHERE a <> NULL and (a <> NULL or a <= NULL); +DROP TABLE t1; + +--echo # End of 5.1 tests diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 2239aafbeec..cfaff76b96b 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -5887,6 +5887,17 @@ get_mm_leaf(RANGE_OPT_PARAM *param, COND *conf_func, Field *field, goto end; } field->table->in_use->variables.sql_mode= orig_sql_mode; + + /* + Any sargable predicate except "<=>" involving NULL as a constant is always + FALSE + */ + if (type != Item_func::EQUAL_FUNC && field->is_real_null()) + { + tree= &null_element; + goto end; + } + str= (uchar*) alloc_root(alloc, key_part->store_length+1); if (!str) goto end; |