diff --git a/mysql-test/r/insert_select.result b/mysql-test/r/insert_select.result
index 0a6a34f9a58..f5ad0c87881 100644
--- a/mysql-test/r/insert_select.result
+++ b/mysql-test/r/insert_select.result
@@ -638,3 +638,15 @@ No	Field	Count
 0	1	100
 0	2	100
 drop table t1, t2;
+CREATE TABLE t1 (
+ID           int(11) NOT NULL auto_increment,
+NO           int(11) NOT NULL default '0',
+SEQ          int(11) NOT NULL default '0',
+PRIMARY KEY  (ID),
+KEY t1$NO    (SEQ,NO)
+) ENGINE=MyISAM;
+INSERT INTO t1 (SEQ, NO) SELECT "1" AS SEQ, IF(MAX(NO) IS NULL, 0, MAX(NO)) + 1 AS NO FROM t1 WHERE (SEQ = 1);
+select SQL_BUFFER_RESULT * from t1 WHERE (SEQ = 1);
+ID	NO	SEQ
+1	1	1
+drop table t1;
diff --git a/mysql-test/t/insert_select.test b/mysql-test/t/insert_select.test
index e1459310bb9..39b8bfcaaaa 100644
--- a/mysql-test/t/insert_select.test
+++ b/mysql-test/t/insert_select.test
@@ -182,3 +182,18 @@ insert into t2 Select null, Field, Count From t1 Where Month=20030901 and Type=2
 select * from t2;
 
 drop table t1, t2;
+
+#
+# BUG#6034 - Error code 124:  Wrong medium type
+#
+CREATE TABLE t1 (
+  ID           int(11) NOT NULL auto_increment,
+  NO           int(11) NOT NULL default '0',
+  SEQ          int(11) NOT NULL default '0',
+  PRIMARY KEY  (ID),
+  KEY t1$NO    (SEQ,NO)
+) ENGINE=MyISAM;
+INSERT INTO t1 (SEQ, NO) SELECT "1" AS SEQ, IF(MAX(NO) IS NULL, 0, MAX(NO)) + 1 AS NO FROM t1 WHERE (SEQ = 1);
+select SQL_BUFFER_RESULT * from t1 WHERE (SEQ = 1);
+drop table t1;
+
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index aea7cb9ed6d..7e48374a8e6 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -398,7 +398,16 @@ JOIN::prepare(Item ***rref_pointer_array,
     goto err;
   }
 #endif
-  if (!procedure && result && result->prepare(fields_list, unit_arg))
+  /*
+    We must not yet prepare the result table if it is the same as one of the 
+    source tables (INSERT SELECT). This is checked in mysql_execute_command()
+    and OPTION_BUFFER_RESULT is added to the select_options. A temporary 
+    table is then used to hold the result. The preparation may disable 
+    indexes on the result table, which may be used during the select, if it
+    is the same table (Bug #6034). Do the preparation after the select phase.
+  */
+  if (! procedure && ! test(select_options & OPTION_BUFFER_RESULT) &&
+      result && result->prepare(fields_list, unit_arg))
     goto err;					/* purecov: inspected */
 
   if (select_lex->olap == ROLLUP_TYPE && rollup_init())
@@ -1043,6 +1052,13 @@ JOIN::exec()
       DBUG_VOID_RETURN;
     }
   }
+  else if (test(select_options & OPTION_BUFFER_RESULT) &&
+           result && result->prepare(fields_list, unit))
+  {
+    error= 1;
+    thd->limit_found_rows= thd->examined_row_count= 0;
+    DBUG_VOID_RETURN;
+  }
 
   if (!tables_list)
   {                                           // Only test of functions