a fix (bug #4304: TRUNCATE <table of type BDB> , wrong result).

mysql-test/r/bdb.result

@@ -1210,3 +1210,10 @@ a	b
 3	three
 4	four
 drop table t1, t2;
+create table t1 (a int, b varchar(30), primary key(a)) engine = bdb;
+insert into t1 values (1,'one');
+commit;
+truncate t1;
+select * from t1;
+a	b
+drop table t1;

mysql-test/t/bdb.test

@@ -850,3 +850,14 @@ insert into t2 (a, b)
   select a, b from t1 where (a, b) in (select a, b from t1);
 select * from t2;
 drop table t1, t2;
+
+#
+# Bug #4304: TRUNCATE <table of type BDB> , wrong result
+#
+
+create table t1 (a int, b varchar(30), primary key(a)) engine = bdb;
+insert into t1 values (1,'one');
+commit;
+truncate t1;
+select * from t1;
+drop table t1;

sql/handler.h

@@ -515,7 +515,8 @@ extern TYPELIB tx_isolation_typelib;
 #define ha_commit(thd) (ha_commit_trans((thd), &((thd)->transaction.all)))
 #define ha_rollback(thd) (ha_rollback_trans((thd), &((thd)->transaction.all)))
 
-#define ha_supports_generate(T) (T != DB_TYPE_INNODB)
+#define ha_supports_generate(T) (T != DB_TYPE_INNODB && \
+                                 T != DB_TYPE_BERKELEY_DB)
 
 bool ha_caching_allowed(THD* thd, char* table_key,
                         uint key_length, uint8 cache_type);