A fix and test case for bug#5510 "inserting Null in AutoIncrement primary

key Column Fails".

mysql-test/r/ps.result

@@ -270,3 +270,22 @@ execute stmt using @var;
 a
 deallocate prepare stmt;
 drop table t1;
+create table t1 (a bigint(20) not null primary key auto_increment);
+insert into t1 (a) values (null);
+select * from t1;
+a
+1
+prepare stmt from "insert into t1 (a) values (?)";
+set @var=null;
+execute stmt using @var;
+select * from t1;
+a
+1
+2
+drop table t1;
+create table t1 (a timestamp not null);
+prepare stmt from "insert into t1 (a) values (?)";
+execute stmt using @var;
+select * from t1;
+deallocate prepare stmt;
+drop table t1;

mysql-test/r/ps_2myisam.result

@@ -1015,7 +1015,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 1	one

mysql-test/r/ps_3innodb.result

@@ -1015,7 +1015,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 0	two

mysql-test/r/ps_4heap.result

@@ -1016,7 +1016,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 1	one

mysql-test/r/ps_5merge.result

@@ -1058,7 +1058,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 3	three
@@ -2253,7 +2253,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 3	three

mysql-test/r/ps_6bdb.result

@@ -1015,7 +1015,7 @@ set @arg00=NULL;
 set @arg01=2;
 execute stmt1 using @arg00, @arg01;
 Warnings:
-Warning	1265	Data truncated for column 'a' at row 1
+Warning	1263	Data truncated; NULL supplied to NOT NULL column 'a' at row 1
 select a,b from t1;
 a	b
 0	two

mysql-test/t/ps.test

@@ -278,3 +278,29 @@ execute stmt using @var;
 deallocate prepare stmt;
 drop table t1;
 
+# 
+# BUG#5510 "inserting Null in AutoIncrement primary key Column Fails" 
+# (prepared statements) 
+# The cause: misuse of internal MySQL 'Field' API.
+# 
+
+create table t1 (a bigint(20) not null primary key auto_increment);
+insert into t1 (a) values (null);
+select * from t1;
+prepare stmt from "insert into t1 (a) values (?)";
+set @var=null;
+execute stmt using @var;
+select * from t1;
+drop table t1;
+#
+# check the same for timestamps
+#
+create table t1 (a timestamp not null);
+prepare stmt from "insert into t1 (a) values (?)";
+execute stmt using @var;
+--disable_result_log
+select * from t1;
+--enable_result_log
+deallocate prepare stmt;
+drop table t1;
+

sql/item.cc

@@ -891,7 +891,7 @@ int Item_param::save_in_field(Field *field, bool no_conversions)
     return field->store(str_value.ptr(), str_value.length(),
                         str_value.charset());
   case NULL_VALUE:
-    return set_field_to_null(field);
+    return set_field_to_null_with_conversions(field, no_conversions);
   case NO_VALUE:
   default:
     DBUG_ASSERT(0);