1 files changed, 33 insertions, 31 deletions

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 4750fe1386f..28235ba48a3 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -680,33 +680,12 @@ TABLE_LIST *find_table_in_list(TABLE_LIST *table,
                                const char *db_name,
                                const char *table_name)
 {
-  if (lower_case_table_names)
+  for (; table; table= *(TABLE_LIST **) ((char*) table + offset))
   {
-    for (; table; table= *(TABLE_LIST **) ((char*) table + offset))
-    {
-      if ((table->table == 0 || table->table->s->tmp_table == NO_TMP_TABLE) &&
-          ((!strcmp(table->db, db_name) &&
-            !strcmp(table->table_name, table_name)) ||
-           (table->view &&
-            !my_strcasecmp(table_alias_charset,
-                           table->db, db_name) &&
-            !my_strcasecmp(table_alias_charset,
-                           table->table->alias, table_name))))
-        break;
-    }
-  }
-  else
-  {
-    for (; table; table= *(TABLE_LIST **) ((char*) table + offset))
-    {
-      if ((table->table == 0 || table->table->s->tmp_table == NO_TMP_TABLE) &&
-          ((!strcmp(table->db, db_name) &&
-            !strcmp(table->table_name, table_name)) ||
-           (table->view &&
-            !strcmp(table->table->s->db, db_name) &&
-            !strcmp(table->table->alias, table_name))))
-        break;
-    }
+    if ((table->table == 0 || table->table->s->tmp_table == NO_TMP_TABLE) &&
+        strcmp(table->db, db_name) == 0 &&
+        strcmp(table->table_name, table_name) == 0)
+      break;
   }
   return table;
 }
@@ -717,8 +696,25 @@ TABLE_LIST *find_table_in_list(TABLE_LIST *table,
 
   SYNOPSIS
     unique_table()
-    table       table which should be chaked
-    table_list  list of tables
+    table                 table which should be chaked
+    table_list            list of tables
+
+  NOTE: to exclude derived tables from check we use following mechanism:
+    a) during derived table processing set THD::derived_tables_processing
+    b) JOIN::prepare set SELECT::exclude_from_table_unique_test if
+       THD::derived_tables_processing set. (we can't use JOIN::execute
+       because for PS we perform only JOIN::prepare, but we can't set this
+       flag in JOIN::prepare if we are not sure that we are in derived table
+       processing loop, because multi-update call fix_fields() for some its
+       items (which mean JOIN::prepare for subqueries) before unique_table
+       call to detect which tables should be locked for write).
+    c) unique_table skip all tables which belong to SELECT with
+       SELECT::exclude_from_table_unique_test set.
+    Also SELECT::exclude_from_table_unique_test used to exclude from check
+    tables of main SELECT of multi-delete and multi-update
+
+    TODO: when we will have table/view change detection we can do this check
+          only once for PS/SP
 
   RETURN
     found duplicate
@@ -758,11 +754,17 @@ TABLE_LIST* unique_table(TABLE_LIST *table, TABLE_LIST *table_list)
   for(;;)
   {
     if (!(res= find_table_in_global_list(table_list, d_name, t_name)) ||
-        !res->table || res->table != table->table)
+        (!res->table || res->table != table->table) &&
+        (res->select_lex && !res->select_lex->exclude_from_table_unique_test))
       break;
-    /* if we found entry of this table try again. */
+    /*
+      If we found entry of this table or or table of SELECT which already
+      processed in derived table or top select of multi-update/multi-delete
+      (exclude_from_table_unique_test).
+    */
     table_list= res->next_global;
-    DBUG_PRINT("info", ("found same copy of table"));
+    DBUG_PRINT("info",
+               ("found same copy of table or table which we should skip"));
   }
   DBUG_RETURN(res);
 }