LP:806510 - Wrong result with derived table, impossible where , derived_merge=on and EXISTS in maria-5.3

Requires derived_merge=on .Not repeatable before WL#106 .

The following query

SELECT *
FROM (SELECT * FROM t2 ) AS alias1
WHERE EXISTS (
SELECT t3.f2
FROM t3 , t1
WHERE t1.f3 = t3.f3
AND alias1.f2 != 0
) ;

returns no rows when executed with derived merge and 1 row when executed with no derived table or with derived_merge=off.

Explain:

minimal optimizer switch: derived_merge=off
entire optimizer_switch:

index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=off,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on

test case:

CREATE TABLE t1 ( f3 int) ;
INSERT IGNORE INTO t1 VALUES (8),(0);

CREATE TABLE t2 ( f2 int) ;
INSERT IGNORE INTO t2 VALUES (4),(NULL);

CREATE TABLE t3 ( f2 int, f3 int) ;
INSERT IGNORE INTO t3 VALUES (7,8);

SELECT *
FROM (SELECT * FROM t2 ) AS alias1
WHERE EXISTS (
SELECT t3.f2
FROM t3 , t1
WHERE t1.f3 = t3.f3
AND alias1.f2 != 0
) ;