Another bugfix for #615

Looks a bit nicer than previous one


mysql-test/r/insert.result:
  Test results added
mysql-test/t/insert.test:
  testcase for the bug added
sql/field.h:
  Field::set_default fixed
sql/field_conv.cc:
  Now we can just replace field->reset() with field->set_default() here

mysql-test/r/insert.result

@@ -58,6 +58,16 @@ skr	2
 test	1
 test	2
 drop table t1;
+create table t1 (id int NOT NULL DEFAULT 8);
+insert into t1 values(NULL);
+Column 'id' cannot be null
+insert into t1 values (1), (NULL), (2);
+select * from t1;
+id
+1
+8
+2
+drop table t1;
 drop database if exists foo;
 create database foo;
 use foo;

mysql-test/t/insert.test

@@ -50,6 +50,17 @@ insert into t1 values ('rts',NULL),('rts',NULL),('test',NULL);
 select * from t1;
 drop table t1;
 
+#
+#Test of behaviour with INSERT VALUES (NULL)
+#
+
+create table t1 (id int NOT NULL DEFAULT 8);
+-- error 1048
+insert into t1 values(NULL);
+insert into t1 values (1), (NULL), (2);
+select * from t1;
+drop table t1;
+
 #
 # Test of mysqld crash with fully qualified column names
 #
@@ -60,3 +71,4 @@ use foo;
 create table t1 (c int);
 insert into foo.t1 set foo.t1.c = '1';
 drop database foo;
+

sql/field.h

@@ -72,10 +72,12 @@ public:
   virtual void reset_fields() {}
   virtual void set_default()
   {
-    memcpy(ptr, ptr + table->rec_buff_length, pack_length());
+    my_ptrdiff_t offset = (my_ptrdiff_t) (table->record[2] -
+					  table->record[0]);
+    memcpy(ptr, ptr + offset, pack_length());
     if (null_ptr)
       *null_ptr= ((*null_ptr & (uchar) ~null_bit) |
-		  null_ptr[table->rec_buff_length] & null_bit);
+		  null_ptr[offset] & null_bit);
   }
   virtual bool binary() const { return 1; }
   virtual bool zero_pack() const { return 1; }

sql/field_conv.cc

@@ -118,10 +118,9 @@ set_field_to_null(Field *field)
     field->reset();
     return 0;
   }
-  field->reset();
+  field->set_default();
   if (current_thd->count_cuted_fields)
   {
-    field->set_default();
     current_thd->cuted_fields++;		// Increment error counter
     return 0;
   }
@@ -171,12 +170,11 @@ set_field_to_null_with_conversions(Field *field, bool no_conversions)
     ((Field_timestamp*) field)->set_time();
     return 0;					// Ok to set time to NULL
   }
-  field->reset();
+  field->set_default();
   if (field == field->table->next_number_field)
     return 0;					// field is set in handler.cc
   if (current_thd->count_cuted_fields)
   {
-    field->set_default();
     current_thd->cuted_fields++;		// Increment error counter
     return 0;
   }