LP bug#994275 fix.

In 5.3 we substitute constants in ref access values it can't be null so we do not need add NOT NULL for early NULL filtering.

mysql-test/r/select.result

@@ -5101,3 +5101,15 @@ Warning	1292	Incorrect datetime value: 'aa'
 DROP TABLE t1;
 DROP VIEW v1;
 SET optimizer_switch=@save_optimizer_switch;
+#
+# LP bug#994275 Assertion `real->type() == Item::FIELD_ITEM' failed
+# in add_not_null_conds(JOIN*) with JOIN, ZEROFILL column, PK
+#
+CREATE TABLE t1 ( a INT(6) ZEROFILL );
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 ( b INT PRIMARY KEY );
+INSERT INTO t2 VALUES (3),(4);
+SELECT * FROM t1, t2 WHERE a=3 AND a=b;
+a	b
+drop table t1,t2;
+End of 5.3 tests

mysql-test/r/select_jcl6.result

@@ -5112,6 +5112,18 @@ Warning	1292	Incorrect datetime value: 'aa'
 DROP TABLE t1;
 DROP VIEW v1;
 SET optimizer_switch=@save_optimizer_switch;
+#
+# LP bug#994275 Assertion `real->type() == Item::FIELD_ITEM' failed
+# in add_not_null_conds(JOIN*) with JOIN, ZEROFILL column, PK
+#
+CREATE TABLE t1 ( a INT(6) ZEROFILL );
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 ( b INT PRIMARY KEY );
+INSERT INTO t2 VALUES (3),(4);
+SELECT * FROM t1, t2 WHERE a=3 AND a=b;
+a	b
+drop table t1,t2;
+End of 5.3 tests
 set join_cache_level=default;
 show variables like 'join_cache_level';
 Variable_name	Value

mysql-test/r/select_pkeycache.result

@@ -5101,3 +5101,15 @@ Warning	1292	Incorrect datetime value: 'aa'
 DROP TABLE t1;
 DROP VIEW v1;
 SET optimizer_switch=@save_optimizer_switch;
+#
+# LP bug#994275 Assertion `real->type() == Item::FIELD_ITEM' failed
+# in add_not_null_conds(JOIN*) with JOIN, ZEROFILL column, PK
+#
+CREATE TABLE t1 ( a INT(6) ZEROFILL );
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 ( b INT PRIMARY KEY );
+INSERT INTO t2 VALUES (3),(4);
+SELECT * FROM t1, t2 WHERE a=3 AND a=b;
+a	b
+drop table t1,t2;
+End of 5.3 tests

mysql-test/t/select.test

@@ -4272,3 +4272,18 @@ DROP TABLE t1;
 DROP VIEW v1;
 
 SET optimizer_switch=@save_optimizer_switch;
+
+--echo #
+--echo # LP bug#994275 Assertion `real->type() == Item::FIELD_ITEM' failed
+--echo # in add_not_null_conds(JOIN*) with JOIN, ZEROFILL column, PK
+--echo #
+
+CREATE TABLE t1 ( a INT(6) ZEROFILL );
+INSERT INTO t1 VALUES (1),(2);
+
+CREATE TABLE t2 ( b INT PRIMARY KEY );
+INSERT INTO t2 VALUES (3),(4);
+SELECT * FROM t1, t2 WHERE a=3 AND a=b;
+drop table t1,t2;
+
+--echo End of 5.3 tests

sql/sql_select.cc

@@ -7998,6 +7998,16 @@ static void add_not_null_conds(JOIN *join)
           Item *item= tab->ref.items[keypart];
           Item *notnull;
           Item *real= item->real_item();
+          if (real->basic_const_item())
+          {
+            /*
+              It could be constant instead of field after constant
+              propagation.
+            */
+            DBUG_ASSERT(real->is_expensive() || // prevent early expensive eval
+                        !real->is_null()); // NULLs are not propagated
+            continue;
+          }
           DBUG_ASSERT(real->type() == Item::FIELD_ITEM);
           Item_field *not_null_item= (Item_field*)real;
           JOIN_TAB *referred_tab= not_null_item->field->table->reginfo.join_tab;