support of view to COM_FIELD_LIST added (BUG#5145)

sql/sql_parse.cc:
  support of view to COM_FIELD_LIST added
sql/sql_show.cc:
  support of view to COM_FIELD_LIST added

sql/sql_parse.cc

@@ -1327,6 +1327,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     this so that they will not get logged to the slow query log
   */
   thd->slow_command=FALSE;
+  thd->lex->sql_command= SQLCOM_END; /* to avoid confusing VIEW detectors */
   thd->set_time();
   VOID(pthread_mutex_lock(&LOCK_thread_count));
   thd->query_id=query_id;
@@ -1570,7 +1571,17 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     if (grant_option &&
 	check_grant(thd, SELECT_ACL, &table_list, 2, UINT_MAX, 0))
       break;
+    /* switch on VIEW optimisation: do not fill temporary tables */
+    thd->lex->sql_command= SQLCOM_SHOW_FIELDS;
+    /* init structures for VIEW processing */
+    table_list.select_lex= &(thd->lex->select_lex);
+    mysql_init_query(thd, (uchar*)"", 0);
+    thd->lex->
+      select_lex.table_list.link_in_list((byte*) &table_list,
+                                         (byte**) &table_list.next_local);
+
     mysqld_list_fields(thd,&table_list,fields);
+    thd->lex->unit.cleanup();
     free_items(thd->free_list);
     thd->free_list=0;           /* free_list should never point to garbage */
     break;

sql/sql_show.cc

@@ -1124,14 +1124,19 @@ void
 mysqld_list_fields(THD *thd, TABLE_LIST *table_list, const char *wild)
 {
   TABLE *table;
+  int res;
   DBUG_ENTER("mysqld_list_fields");
   DBUG_PRINT("enter",("table: %s",table_list->real_name));
 
-  if (!(table = open_ltable(thd, table_list, TL_UNLOCK)))
+  table_list->lock_type= TL_UNLOCK;
+  if ((res= open_and_lock_tables(thd, table_list)))
   {
-    send_error(thd);
+    if (res < 0)
+      send_error(thd);
     DBUG_VOID_RETURN;
   }
+  table= table_list->table;
+
   List<Item> field_list;
 
   Field **ptr,*field;