From ff923cc82d23f9806834a2411150e32d30b9f4d9 Mon Sep 17 00:00:00 2001
From: Sergey Glukhov <Sergey.Glukhov@sun.com>
Date: Fri, 17 Apr 2009 12:41:15 +0500
Subject: [PATCH] Bug#44151 using handler commands on information_schema tables
 crashes server information schema tables are based on internal tmp tables
 which are removed after each statement execution. So HANDLER comands can not
 be used with information schema.

mysql-test/r/handler.result:
  test result
mysql-test/t/handler.test:
  test case
sql/sql_handler.cc:
  information schema tables are based on internal tmp tables which are removed
  after each statement execution. So HANDLER comands can not be used with
  information schema.
---
 mysql-test/r/handler.result | 4 ++++
 mysql-test/t/handler.test   | 8 ++++++++
 sql/sql_handler.cc          | 8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/mysql-test/r/handler.result b/mysql-test/r/handler.result
index dc3750e16ea..4906111982f 100644
--- a/mysql-test/r/handler.result
+++ b/mysql-test/r/handler.result
@@ -502,3 +502,7 @@ handler t1_alias READ a next where inexistent > 0;
 ERROR 42S22: Unknown column 'inexistent' in 'field list'
 handler t1_alias close;
 drop table t1;
+USE information_schema;
+HANDLER COLUMNS OPEN;
+ERROR HY000: Incorrect usage of HANDLER OPEN and information_schema
+USE test;
diff --git a/mysql-test/t/handler.test b/mysql-test/t/handler.test
index 6ef216f6ed2..70d4157a272 100644
--- a/mysql-test/t/handler.test
+++ b/mysql-test/t/handler.test
@@ -460,3 +460,11 @@ handler t1_alias read a next;
 handler t1_alias READ a next where inexistent > 0;
 handler t1_alias close;
 drop table t1;
+
+#
+# Bug#44151 using handler commands on information_schema tables crashes server
+#
+USE information_schema;
+--error ER_WRONG_USAGE
+HANDLER COLUMNS OPEN;
+USE test;
diff --git a/sql/sql_handler.cc b/sql/sql_handler.cc
index c376f1b3d1d..721b365a7b9 100644
--- a/sql/sql_handler.cc
+++ b/sql/sql_handler.cc
@@ -190,6 +190,14 @@ bool mysql_ha_open(THD *thd, TABLE_LIST *tables, bool reopen)
                       tables->db, tables->table_name, tables->alias,
                       (int) reopen));
 
+  if (tables->schema_table)
+  {
+    my_error(ER_WRONG_USAGE, MYF(0), "HANDLER OPEN",
+             INFORMATION_SCHEMA_NAME.str);
+    DBUG_PRINT("exit",("ERROR"));
+    DBUG_RETURN(TRUE);
+  }
+
   if (! hash_inited(&thd->handler_tables_hash))
   {
     /*