Merge magare.gmz:/home/kgeorge/mysql/work/B30715-merged-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/work/B30715-merged-5.1-opt

mysql-test/r/func_group.result

@@ -1378,4 +1378,9 @@ SELECT 1 FROM t1 GROUP BY (SELECT SLEEP(0) FROM t1 ORDER BY AVG(DISTINCT a) );
 1
 1
 DROP TABLE t1;
+CREATE TABLE t1 (a int, b date NOT NULL, KEY k1 (a,b));
+SELECT MIN(b) FROM t1 WHERE a=1 AND b>'2007-08-01';
+MIN(b)
+NULL
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/r/type_decimal.result

@@ -812,4 +812,14 @@ select group_concat(f1),group_concat(f2) from t1;
 group_concat(f1)	group_concat(f2)
 -0.123456	0.123456
 drop table t1;
+create table t1 (
+ua_id decimal(22,0) not null,
+ua_invited_by_id decimal(22,0) default NULL,
+primary key(ua_id)
+);
+insert into t1 values (123, NULL), (456, NULL);
+this must not produce error 1048: 
+select * from t1 where ua_invited_by_id not in (select ua_id from t1);
+ua_id	ua_invited_by_id
+drop table t1;
 End of 5.0 tests

mysql-test/t/func_group.test

@@ -880,5 +880,14 @@ SELECT 1 FROM t1 GROUP BY (SELECT SLEEP(0) FROM t1 ORDER BY AVG(DISTINCT a) );
 
 DROP TABLE t1;
 
+#
+# Bug #30715: Assertion failed: item_field->field->real_maybe_null(), file
+# .\opt_sum.cc, line
+#
+
+CREATE TABLE t1 (a int, b date NOT NULL, KEY k1 (a,b));
+SELECT MIN(b) FROM t1 WHERE a=1 AND b>'2007-08-01';
+DROP TABLE t1;
+
 ###
 --echo End of 5.0 tests

mysql-test/t/type_decimal.test

@@ -425,5 +425,20 @@ insert into t1 values (-0.123456,0.123456);
 select group_concat(f1),group_concat(f2) from t1;
 drop table t1;
 
+#
+# BUG#31450 "Query causes error 1048"
+#
+create table t1 (
+  ua_id decimal(22,0) not null,
+  ua_invited_by_id decimal(22,0) default NULL,
+  primary key(ua_id)
+);
+insert into t1 values (123, NULL), (456, NULL);
+
+--echo this must not produce error 1048: 
+select * from t1 where ua_invited_by_id not in (select ua_id from t1);
+
+drop table t1;
+
 --echo End of 5.0 tests
 

sql/item.cc

@@ -4649,7 +4649,7 @@ int Item::save_in_field(Field *field, bool no_conversions)
     my_decimal decimal_value;
     my_decimal *value= val_decimal(&decimal_value);
     if (null_value)
-      return set_field_to_null(field);
+      return set_field_to_null_with_conversions(field, no_conversions);
     field->set_notnull();
     error=field->store_decimal(value);
   }

sql/opt_sum.cc

@@ -295,14 +295,15 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
                  Check if case 1 from above holds. If it does, we should read
                  the skipped tuple.
               */
-              if (ref.key_buff[prefix_len] == 1 && 
-                  /* 
+              if (item_field->field->real_maybe_null() &&
+                  ref.key_buff[prefix_len] == 1 &&
+                  /*
                      Last keypart (i.e. the argument to MIN) is set to NULL by
                      find_key_for_maxmin only if all other keyparts are bound
                      to constants in a conjunction of equalities. Hence, we
                      can detect this by checking only if the last keypart is
                      NULL.
-                  */                     
+                  */
                   (error == HA_ERR_KEY_NOT_FOUND ||
                    key_cmp_if_same(table, ref.key_buff, ref.key, prefix_len)))
               {