Bug#14653504 CRASH WHEN TRUNCATING PARTITIONS FROM A VIEW!

ANALYSIS
--------
 
When we open the view using open_new_frm() ,it doesnt set the
table-list->table variable and any access to table_list->table 
will cause a crash.
 
FIX
---
 
Added a check during execution of the alter partition to return 
error if table is view.

[http://rb.no.oracle.com/rb/r/2001/  Approved by Mattias J ]

sql/sql_partition_admin.cc

@@ -141,7 +141,9 @@ bool Alter_table_truncate_partition_statement::execute(THD *thd)
     TODO: Add support for TRUNCATE PARTITION for NDB and other
           engines supporting native partitioning.
   */
-  if (first_table->table->s->db_type() != partition_hton)
+
+  if (!first_table->table || first_table->view ||
+      first_table->table->s->db_type() != partition_hton)
   {
     my_error(ER_PARTITION_MGMT_ON_NONPARTITIONED, MYF(0));
     DBUG_RETURN(TRUE);