Merge 5.3->5.5

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;

mysql-test/t/null.test

@@ -255,3 +255,31 @@ DESCRIBE t2;
 DROP TABLE t1, t2;
 
 --echo # End of 5.0 tests
+
+--echo #
+--echo # MDEV-4895 Valgrind warnings (Conditional jump or move depends on uninitialised value) in Field_datetime::get_date on GREATEST(..) IS NULL
+--echo #
+
+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;
+SELECT * FROM t1 WHERE concat( dt, '2012-12-21 12:12:12' ) IS NULL;
+
+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;
+SELECT * FROM t1 WHERE concat( dt, '1' ) IS NULL;
+
+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); 
+SELECT * FROM t1 WHERE NOT (concat( dt, '1' ) IS NOT NULL); 
+
+DROP TABLE t1;

sql/item_cmpfunc.cc

@@ -4748,6 +4748,8 @@ Item *and_expressions(Item *a, Item *b, Item **org_item)
 longlong Item_func_isnull::val_int()
 {
   DBUG_ASSERT(fixed == 1);
+  if (const_item() && !args[0]->maybe_null)
+    return 0;
   return args[0]->is_null() ? 1: 0;
 }
 
@@ -4755,6 +4757,8 @@ longlong Item_is_not_null_test::val_int()
 {
   DBUG_ASSERT(fixed == 1);
   DBUG_ENTER("Item_is_not_null_test::val_int");
+  if (const_item() && !args[0]->maybe_null)
+    DBUG_RETURN(1);
   if (args[0]->is_null())
   {
     DBUG_PRINT("info", ("null"));

sql/sql_select.cc

@@ -13748,7 +13748,7 @@ internal_remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
         Propagate the newly formed multiple equalities to
         the all AND/OR levels of cond 
       */
-      bool is_simplifiable_cond= true;
+      bool is_simplifiable_cond= false;
       propagate_new_equalities(thd, cond, cond_equalities,
                                cond_equal->upper_levels,
                                &is_simplifiable_cond);
@@ -13759,7 +13759,7 @@ internal_remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
       */ 
       if (is_simplifiable_cond)
       {
-        if (!(cond= remove_eq_conds(thd, cond, cond_value)))
+        if (!(cond= internal_remove_eq_conds(thd, cond, cond_value)))
           return cond;
       }          
     }