Fix for bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement

   restore original 'lex->query_tables' table list after
   processing of information schema table
   remove unnecessary operations


mysql-test/r/ps.result:
  Fix for bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement
mysql-test/t/ps.test:
  Fix for bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement
sql/sql_lex.h:
  Fix for bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement
sql/sql_show.cc:
  Fix for bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement

1 files changed, 21 insertions, 0 deletions

diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test
index 1af84119b79..271d553e221 100644
--- a/mysql-test/t/ps.test
+++ b/mysql-test/t/ps.test
@@ -540,3 +540,24 @@ deallocate prepare stmt;
 
 drop table t1,t2;
 
+
+#
+# Bug#9383: INFORMATION_SCHEMA.COLUMNS, JOIN, Crash, prepared statement
+#
+
+eval SET @aux= "SELECT COUNT(*)
+                FROM INFORMATION_SCHEMA.COLUMNS A,
+                INFORMATION_SCHEMA.COLUMNS B
+                WHERE A.TABLE_SCHEMA = B.TABLE_SCHEMA
+                AND A.TABLE_NAME = B.TABLE_NAME
+                AND A.COLUMN_NAME = B.COLUMN_NAME AND
+                A.TABLE_NAME = 'user'";
+
+let $exec_loop_count= 3;
+eval prepare my_stmt from @aux;
+while ($exec_loop_count)
+{
+  eval execute my_stmt;
+  dec $exec_loop_count;
+}
+deallocate prepare my_stmt;