bzr commit into mysql-5.1 branch (kristofer.pettersson:2690) Bug#29507

[Kristofer Pettersson]

#At file:///home/thek/Development/cpp/mysqlbzr/mysql-5.1-bug40386/

 2690 Kristofer Pettersson	2008-11-03
      Bug#29507 TRUNCATE shows to many rows effected
      
      TRUNCATE TABLE for InnoDB tables returned a count showing an approximation
      of the number of rows affected to gain efficiency.
      Now the statement always returns 0 rows affected for clarity.
modified:
  sql/sql_delete.cc

per-file messages:
  sql/sql_delete.cc
    * Set row count to 0 if auto increment was reset which can happen
    if TRUNCATE TABLE was issued.
=== modified file 'sql/sql_delete.cc'
--- a/sql/sql_delete.cc	2008-07-17 18:26:55 +0000
+++ b/sql/sql_delete.cc	2008-11-03 13:08:42 +0000
@@ -398,7 +398,11 @@ cleanup:
   free_underlaid_joins(thd, select_lex);
   if (error < 0 || (thd->lex->ignore && !thd->is_fatal_error))
   {
-    thd->row_count_func= deleted;
+    /*
+      If a TRUNCATE TABLE was issued, the number of rows should be reported as
+      zero since the exact number is unknown.
+    */
+    thd->row_count_func= reset_auto_increment ? 0 : deleted;
     my_ok(thd, (ha_rows) thd->row_count_func);
     DBUG_PRINT("info",("%ld records deleted",(long) deleted));
   }