Bug#27990: Wrong info in MYSQL_FIELD struct members when a tmp table was used.

The change_to_use_tmp_fields function leaves the orig_table member of an
expression's tmp table field filled for the new Item_field being created.
Later orig_table is used by the Field::make_field function to provide some
info about original table and field name to a user. This is ok for a field
but for an expression it should be empty.

The change_to_use_tmp_fields function now resets orig_table member of
an expression's tmp table field to prevent providing a wrong info to a user.
The Field::make_field function now resets the table_name and the org_col_name
variables when the orig_table is set to 0.

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

sql/field.cc

@@ -1282,15 +1282,25 @@ void Field_num::add_zerofill_and_unsigned(String &res) const
 
 void Field::make_field(Send_field *field)
 {
-  if (orig_table->s->table_cache_key && *(orig_table->s->table_cache_key))
+  if (orig_table && orig_table->s->table_cache_key &&
+      *(orig_table->s->table_cache_key))
   {
     field->org_table_name= orig_table->s->table_name;
     field->db_name= orig_table->s->table_cache_key;
   }
   else
     field->org_table_name= field->db_name= "";
+  if (orig_table)
+  {
     field->table_name= orig_table->alias;
-  field->col_name= field->org_col_name= field_name;
+    field->org_col_name= field_name;
+  }
+  else
+  {
+    field->table_name= "";
+    field->org_col_name= "";
+  }
+  field->col_name= field_name;
   field->charsetnr= charset()->number;
   field->length=field_length;
   field->type=type();

sql/sql_select.cc

@@ -14119,6 +14119,9 @@ change_to_use_tmp_fields(THD *thd, Item **ref_pointer_array,
 	  item_field= (Item*) new Item_field(field);
 	if (!item_field)
 	  DBUG_RETURN(TRUE);                    // Fatal error
+
+        if (item->real_item()->type() != Item::FIELD_ITEM)
+          field->orig_table= 0;
 	item_field->name= item->name;
 #ifndef DBUG_OFF
 	if (_db_on_ && !item_field->name)

tests/mysql_client_test.c

@@ -15486,7 +15486,7 @@ static void test_bug21635()
   char *query_end;
   MYSQL_RES *result;
   MYSQL_FIELD *field;
-  unsigned int field_count, i;
+  unsigned int field_count, i, j;
   int rc;
 
   DBUG_ENTER("test_bug21635");
@@ -15502,6 +15502,12 @@ static void test_bug21635()
   myquery(rc);
   rc= mysql_query(mysql, "CREATE TABLE t1 (i INT)");
   myquery(rc);
+  /*
+    We need this loop to ensure correct behavior with both constant and
+    non-constant tables.
+  */
+  for (j= 0; j < 2 ; j++)
+  {
     rc= mysql_query(mysql, "INSERT INTO t1 VALUES (1)");
     myquery(rc);
 
@@ -15524,6 +15530,7 @@ static void test_bug21635()
     }
 
     mysql_free_result(result);
+  }
   rc= mysql_query(mysql, "DROP TABLE t1");
   myquery(rc);