Fix for bug#18437 "Wrong values inserted with a before update trigger on

NDB table".

SQL-layer was not marking fields which were used in triggers as such. As
result these fields were not always properly retrieved/stored by handler
layer. So one might got wrong values or lost changes in triggers for NDB,
Federated and possibly InnoDB tables.
This fix solves the problem by marking fields used in triggers
appropriately.

Also this patch contains the following cleanup of ha_ndbcluster code:

We no longer rely on reading LEX::sql_command value in handler in order
to determine if we can enable optimization which allows us to handle REPLACE
statement in more efficient way by doing replaces directly in write_row()
method without reporting error to SQL-layer.
Instead we rely on SQL-layer informing us whether this optimization
applicable by calling handler::extra() method with
HA_EXTRA_WRITE_CAN_REPLACE flag.
As result we no longer apply this optimzation in cases when it should not
be used (e.g. if we have on delete triggers on table) and use in some
additional cases when it is applicable (e.g. for LOAD DATA REPLACE).

Finally this patch includes fix for bug#20728 "REPLACE does not work
correctly for NDB table with PK and unique index".
  
This was yet another problem which was caused by improper field mark-up.
During row replacement fields which weren't explicity used in REPLACE
statement were not marked as fields to be saved (updated) so they have
retained values from old row version. The fix is to mark all table
fields as set for REPLACE statement. Note that in 5.1 we already solve
this problem by notifying handler that it should save values from all
fields only in case when real replacement happens.

1 files changed, 42 insertions, 0 deletions

diff --git a/mysql-test/t/federated.test b/mysql-test/t/federated.test
index 80b31c610a2..6e53b1e3adb 100644
--- a/mysql-test/t/federated.test
+++ b/mysql-test/t/federated.test
@@ -1310,4 +1310,46 @@ connection slave;
 DROP TABLE federated.bug_17377_table;
 
 
+# 
+# Additional test for bug#18437 "Wrong values inserted with a before
+# update trigger on NDB table". SQL-layer didn't properly inform
+# handler about fields which were read and set in triggers. In some
+# cases this resulted in incorrect (garbage) values of OLD variables
+# and lost changes to NEW variables.
+# Since for federated engine only operation which is affected by wrong
+# fields mark-up is handler::write_row() this file constains coverage
+# for ON INSERT triggers only. Tests for other types of triggers reside
+# in ndb_trigger.test.
+#
+--disable_warnings
+drop table if exists federated.t1;
+--enable_warnings
+create table federated.t1 (a int, b int, c int);
+connection master;
+--disable_warnings
+drop table if exists federated.t1;
+drop table if exists federated.t2;
+--enable_warnings
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval create table federated.t1 (a int,  b int, c int) engine=federated connection='mysql://root@127.0.0.1:$SLAVE_MYPORT/federated/t1';
+create trigger federated.t1_bi before insert on federated.t1 for each row set new.c= new.a * new.b;
+create table federated.t2 (a int, b int);
+insert into federated.t2 values (13, 17), (19, 23);
+# Each of three statements should correctly set values for all three fields
+# insert
+insert into federated.t1 (a, b) values (1, 2), (3, 5), (7, 11);
+select * from federated.t1;
+delete from federated.t1;
+# insert ... select
+insert into federated.t1 (a, b) select * from federated.t2;
+select * from federated.t1;
+delete from federated.t1;
+# load
+load data infile '../std_data_ln/loaddata5.dat' into table federated.t1 fields terminated by '' enclosed by '' ignore 1 lines (a, b);
+select * from federated.t1;
+drop tables federated.t1, federated.t2;
+
+connection slave;
+drop table federated.t1;
+
 source include/federated_cleanup.inc;