From 446af393375dee2ba15b3c9908bdb087de5721fd Mon Sep 17 00:00:00 2001
From: "mikael@dator5.(none)" <>
Date: Thu, 22 Jun 2006 10:46:02 -0400
Subject: [PATCH] BUG#20583: index_last causes crash when performed on single
 partition

---
 mysql-test/r/partition.result | 8 ++++++++
 mysql-test/t/partition.test   | 9 +++++++++
 sql/ha_partition.cc           | 3 ++-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/partition.result b/mysql-test/r/partition.result
index fa1baaec07e..f6f5073f241 100644
--- a/mysql-test/r/partition.result
+++ b/mysql-test/r/partition.result
@@ -1043,4 +1043,12 @@ alter table t1 add partition (partition p2 values in (3));
 alter table t1 drop partition p2;
 use test;
 drop database db99;
+create table t1 (a int, index(a))
+partition by hash(a);
+insert into t1 values (1),(2);
+select * from t1 ORDER BY a DESC;
+a
+2
+1
+drop table t1;
 End of 5.1 tests
diff --git a/mysql-test/t/partition.test b/mysql-test/t/partition.test
index f62bb2dcd01..758a551cc95 100644
--- a/mysql-test/t/partition.test
+++ b/mysql-test/t/partition.test
@@ -1199,4 +1199,13 @@ alter table t1 drop partition p2;
 use test;
 drop database db99;
 
+#
+# Bug 20583 Partitions: Crash using index_last
+#
+create table t1 (a int, index(a))
+partition by hash(a);
+insert into t1 values (1),(2);
+select * from t1 ORDER BY a DESC;
+drop table t1;
+
 --echo End of 5.1 tests
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index 93fb6409f9f..293085a2630 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -3399,7 +3399,8 @@ int ha_partition::common_first_last(byte *buf)
 
   if ((error= partition_scan_set_up(buf, FALSE)))
     return error;
-  if (!m_ordered_scan_ongoing)
+  if (!m_ordered_scan_ongoing &&
+      m_index_scan_type != partition_index_last)
     return handle_unordered_scan_next_partition(buf);
   return handle_ordered_index_scan(buf);
 }