bug#4008 - merge table cannot determine what key caused "dupl. key" error

myisammrg/myrg_write.c:
  set info->current_table correctly
mysql-test/r/merge.result:
  bug#4008
mysql-test/t/merge.test:
  bug#4008

1 files changed, 8 insertions, 0 deletions

diff --git a/mysql-test/t/merge.test b/mysql-test/t/merge.test
index 1f61e200613..cf55c26fb69 100644
--- a/mysql-test/t/merge.test
+++ b/mysql-test/t/merge.test
@@ -190,6 +190,14 @@ select * from t5 order by a,b;
 select * from t6 order by a,b;
 insert into t1 values (99,NULL);
 select * from t4 where a+0 > 90;
+# bug#4008 - cannot determine a unique key that caused "dupl. key error"
+--error 1062
+insert t5 values (1,1);
+--error 1062
+insert t6 values (2,1);
+insert t5 values (1,1) on duplicate key update b=b+10;
+insert t6 values (2,1) on duplicate key update b=b+20;
+select * from t5 where a < 3;
 drop table t6, t5, t4, t3, t2, t1;
 
 CREATE TABLE t1 (  a int(11) NOT NULL default '0',  b int(11) NOT NULL default '0',  PRIMARY KEY  (a,b)) ENGINE=MyISAM;