From 3d37b67b2bf978c6755508aef0e0a1e64257f41c Mon Sep 17 00:00:00 2001
From: unknown <sanja@montyprogram.com>
Date: Tue, 15 May 2012 08:31:07 +0300
Subject: [PATCH] Fix for LP bug#998516

If we did nothing in resolving unique table conflict we should not retry (it leed to infinite loop).
Now we retry (recheck) unique table check only in case if we materialized a table.
---
 mysql-test/r/derived_view.result | 18 ++++++++++++++++++
 mysql-test/t/derived_view.test   | 13 +++++++++++++
 sql/sql_base.cc                  |  2 +-
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/derived_view.result b/mysql-test/r/derived_view.result
index ef8e0a2a9cb..9e6d6db9314 100644
--- a/mysql-test/r/derived_view.result
+++ b/mysql-test/r/derived_view.result
@@ -2087,6 +2087,24 @@ a	b
 drop table t1;
 set optimizer_switch=@save978847_optimizer_switch;
 #
+# LP bug998516 Server hangs on INSERT .. SELECT with derived_merge,
+# FROM subquery, UNION 
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
+INSERT INTO t1 SELECT * FROM ( SELECT * FROM t1 ) AS alias UNION SELECT * FROM t2;
+select * from t1;
+a
+1
+2
+1
+2
+3
+4
+drop table t1,t2;
+#
 # end of 5.3 tests
 #
 set optimizer_switch=@exit_optimizer_switch;
diff --git a/mysql-test/t/derived_view.test b/mysql-test/t/derived_view.test
index 3320ca25136..30811be2934 100644
--- a/mysql-test/t/derived_view.test
+++ b/mysql-test/t/derived_view.test
@@ -1437,6 +1437,19 @@ drop table t1;
 
 set optimizer_switch=@save978847_optimizer_switch;
 
+
+--echo #
+--echo # LP bug998516 Server hangs on INSERT .. SELECT with derived_merge,
+--echo # FROM subquery, UNION 
+--echo #
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
+INSERT INTO t1 SELECT * FROM ( SELECT * FROM t1 ) AS alias UNION SELECT * FROM t2;
+select * from t1;
+drop table t1,t2;
+
 --echo #
 --echo # end of 5.3 tests
 --echo #
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 38e56a49767..628a4bfd919 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -1739,8 +1739,8 @@ retry:
                  ("convert merged to materialization to resolve the conflict"));
       derived->change_refs_to_fields();
       derived->set_materialized_derived();
+      goto retry;
     }
-    goto retry;
   }
   DBUG_RETURN(res);
 }