A fix and a test case for Bug#13488 "Left outer join query incorrectly

gives MYSQL_DATA_TRUNCATED"


sql/sql_cursor.cc:
  A partial fix for Bug#13488 "Left outer join query incorrectly gives 
  MYSQL_DATA_TRUNCATED": send the correct metadata of the cursor
  result set at execute. The full fix would be to make sure that
  the metadata doesn't change between prepare and execute.
tests/mysql_client_test.c:
  A test case for Bug#13488 "Left outer join query incorrectly gives 
  MYSQL_DATA_TRUNCATED"

1 files changed, 18 insertions, 8 deletions

diff --git a/sql/sql_cursor.cc b/sql/sql_cursor.cc
index e8da691ea18..07be9efa6ac 100644
--- a/sql/sql_cursor.cc
+++ b/sql/sql_cursor.cc
@@ -558,6 +558,24 @@ int Materialized_cursor::open(JOIN *join __attribute__((unused)))
        result->prepare(item_list, &fake_unit) ||
        table->file->ha_rnd_init(TRUE));
   thd->restore_active_arena(this, &backup_arena);
+  if (rc == 0)
+  {
+    /*
+      Now send the result set metadata to the client. We need to do it
+      here, as in Select_materialize::send_fields the exact column types
+      are not yet known. The new types may differ from the original ones
+      sent at prepare if some of them were altered by MySQL HEAP tables
+      mechanism -- used when create_tmp_field_from_item may alter the
+      original column type.
+
+      We can't simply supply SEND_EOF flag to send_fields, because
+      send_fields doesn't flush the network buffer.
+    */
+    rc= result->send_fields(item_list, Protocol::SEND_NUM_ROWS);
+    thd->server_status|= SERVER_STATUS_CURSOR_EXISTS;
+    result->send_eof();
+    thd->server_status&= ~SERVER_STATUS_CURSOR_EXISTS;
+  }
   return rc;
 }
 
@@ -647,14 +665,6 @@ bool Select_materialize::send_fields(List<Item> &list, uint flags)
   if (create_result_table(unit->thd, unit->get_unit_column_types(),
                           FALSE, thd->options | TMP_TABLE_ALL_COLUMNS, ""))
     return TRUE;
-  /*
-    We can't simply supply SEND_EOF flag to send_fields, because send_fields
-    doesn't flush the network buffer.
-  */
-  rc= result->send_fields(list, Protocol::SEND_NUM_ROWS);
-  thd->server_status|= SERVER_STATUS_CURSOR_EXISTS;
-  result->send_eof();
-  thd->server_status&= ~SERVER_STATUS_CURSOR_EXISTS;
   return rc;
 }