Forward port r315 from branches/5.0:

Fix a bug #18077 InnoDB uses full explicit table locks in
stored FUNCTION.

handler/ha_innodb.cc

@@ -6956,13 +6956,14 @@ ha_innobase::store_lock(
 		< TL_WRITE_CONCURRENT_INSERT.
 
 		We especially allow multiple writers if MySQL is at the
-		start of a stored procedure call (SQLCOM_CALL)
-		(MySQL does have thd->in_lock_tables TRUE there). */
+		start of a stored procedure call (SQLCOM_CALL) or a
+		stored function call (MySQL does have thd->in_lock_tables
+		TRUE there). */
 
 		if ((lock_type >= TL_WRITE_CONCURRENT_INSERT
 		&& lock_type <= TL_WRITE)
-			&& (!thd->in_lock_tables
-				|| thd->lex->sql_command == SQLCOM_CALL)
+		&& !(thd->in_lock_tables
+			&& thd->lex->sql_command == SQLCOM_LOCK_TABLES)
 		&& !thd->tablespace_op
 		&& thd->lex->sql_command != SQLCOM_TRUNCATE
 		&& thd->lex->sql_command != SQLCOM_OPTIMIZE