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| author | unknown <timour@askmonty.org> | 2013-08-20 17:08:03 +0300 |
|---|---|---|
| committer | unknown <timour@askmonty.org> | 2013-08-20 17:08:03 +0300 |
| commit | 5fdb531d77e025cdf1738c424207b13e0a7608f5 (patch) | |
| tree | feb602ab7fe1fbd0a363da89298aedb3227a73b6 /mysql-test/r | |
| parent | 008371b627c8a8ddbc682820d3c4f9358fa1b950 (diff) | |
| download | mariadb-git-5fdb531d77e025cdf1738c424207b13e0a7608f5.tar.gz | |
Fix bug MDEV-4895 Valgrind warnings (Conditional jump or move depends on uninitialised value) in Field_datetime::get_date on GREATEST(..) IS NULL
Analysis:
The cause of the valgrind warning was an attempt to evaluate a Field that was not yet read.
The reason was that on one hand Item_func_isnotnull was marked as constant by
Item_func_isnotnull::update_used_tables, and this allowed eval_const_cond() to be called.
On the other hand Item_func_isnotnull::val_int() evaluated its argument as if it was not
constant.
Solution:
The fix make sure that Item_func_isnotnull::val_int() doesn't evaluate its argument when
it is constant and cannot be NULL, because the result is known in this case.
Diffstat (limited to 'mysql-test/r')
| -rw-r--r-- | mysql-test/r/null.result | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/mysql-test/r/null.result b/mysql-test/r/null.result index ac72e1e303e..647b943df1e 100644 --- a/mysql-test/r/null.result +++ b/mysql-test/r/null.result @@ -343,3 +343,33 @@ Field Type Null Key Default Extra IFNULL(NULL, b) decimal(1,0) YES NULL DROP TABLE t1, t2; # End of 5.0 tests +# +# MDEV-4895 Valgrind warnings (Conditional jump or move depends on uninitialised value) in Field_datetime::get_date on GREATEST(..) IS NULL +# +CREATE TABLE t1 (dt DATETIME NOT NULL); +INSERT INTO t1 VALUES (NOW()),(NOW()); +EXPLAIN +SELECT * FROM t1 WHERE concat( dt, '2012-12-21 12:12:12' ) IS NULL; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE +SELECT * FROM t1 WHERE concat( dt, '2012-12-21 12:12:12' ) IS NULL; +dt +drop table t1; +CREATE TABLE t1 (dt INT NOT NULL); +INSERT INTO t1 VALUES (1),(2); +EXPLAIN +SELECT * FROM t1 WHERE concat( dt, '1' ) IS NULL; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE +SELECT * FROM t1 WHERE concat( dt, '1' ) IS NULL; +dt +drop table t1; +CREATE TABLE t1 (dt INT NOT NULL); +INSERT INTO t1 VALUES (1),(2); +EXPLAIN +SELECT * FROM t1 WHERE NOT (concat( dt, '1' ) IS NOT NULL); +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE +SELECT * FROM t1 WHERE NOT (concat( dt, '1' ) IS NOT NULL); +dt +drop table t1; |