reset() split in 2 function clear() & add()

aggregate function reinitialization (if no rows was found) made with help of clear()
(fixed BUG#860)


mysql-test/r/subselect.result:
  test for BUG#860
mysql-test/t/subselect.test:
  test for BUG#860
sql/item_sum.cc:
  reset() replaced with clear()
sql/item_sum.h:
  reset() replaced with clear()
  (reset now is just composition of clear() and add())
sql/item_uniq.h:
  reset() replaced with clear()
sql/sql_select.cc:
  removed NULL value assigment, now it will be done by clear() call
  function for clearing if there was not found any row in group
sql/sql_select.h:
  function for clearing if there was not found any row in group

1 files changed, 9 insertions, 0 deletions

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index cf02eda9aba..dd8aeba8563 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -1352,3 +1352,12 @@ ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_
 select * from t1 where s1 > any (select max(s2) from t1);
 ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '>'
 drop table t1;
+create table t1(toid int,rd int);
+create table t2(userid int,pmnew int,pmtotal int);
+insert into t2 values(1,0,0),(2,0,0);
+insert into t1 values(1,0),(1,0),(1,0),(1,12),(1,15),(1,123),(1,12312),(1,12312),(1,123),(2,0),(2,0),(2,1),(2,2);
+select userid,pmtotal,pmnew, (select count(rd) from t1 where toid=t2.userid) calc_total, (select count(rd) from t1 where rd=0 and toid=t2.userid) calc_new from t2 where userid in (select distinct toid from t1);
+userid	pmtotal	pmnew	calc_total	calc_new
+1	0	0	9	3
+2	0	0	4	2
+drop table t1, t2;