From 7f64144bf0a2bb0ec7ada60685993a1c9bba80c1 Mon Sep 17 00:00:00 2001
From: "igor@olga.mysql.com" <>
Date: Wed, 11 Jul 2007 18:45:35 -0700
Subject: Fixed bug #29604. A bug in the restore_prev_nj_state function allowed
 interleaving inner tables of outer join operations with outer tables. With
 the current implementation of the nested loops algorithm it could lead to
 wrong result sets for queries with nested outer joins. Another bug in this
 procedure effectively blocked evaluation of some valid execution plans for
 queries with nested outer joins.

---
 sql/sql_select.cc | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

(limited to 'sql')

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 9d27ab4bb4e..c62a19b2752 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -8486,9 +8486,15 @@ static void restore_prev_nj_state(JOIN_TAB *last)
 {
   TABLE_LIST *last_emb= last->table->pos_in_table_list->embedding;
   JOIN *join= last->join;
-  while (last_emb && !(--last_emb->nested_join->counter))
+  while (last_emb)
   {
-    join->cur_embedding_map &= last_emb->nested_join->nj_map;
+    if (!(--last_emb->nested_join->counter))
+      join->cur_embedding_map&= ~last_emb->nested_join->nj_map;
+    else if (last_emb->nested_join->join_list.elements-1 ==
+             last_emb->nested_join->counter) 
+      join->cur_embedding_map|= last_emb->nested_join->nj_map;
+    else
+      break;
     last_emb= last_emb->embedding;
   }
 }
-- 
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