Merge lp:~laurynas-biveinis/percona-server/bug890404-5.1 into lp:percona-server/5.1

[Laurynas Biveinis]

Fix bug 890404 (valgrind warning from innodb_fake_changes patch) and
improve the fake changes testcase.

The Valgrind warning in bug 890404 is "conditional jump depends on
uninitialized value(s)" and the value in question is roll_ptr in
btr_cur_pessimistic_update(). Normally roll_ptr is set by
the btr_cur_upd_lock_and_undo() call and then read by one of the
row_upd_index_entry_sys_field() calls. With the fake changes enabled,
roll_ptr write is skipped but read is not.

Fixed by skipping row_upd_index_entry_sys_field() calls in case of
fake changes.

Extended the percona_innodb_fake_changes testcase by dropping table t2
at the start too if exists, and by adding table checks and checksum
comparisons for tables with data that have fake changes workload to
see that fake changes do not cause corruption nor leak through.

http://jenkins.percona.com/job/percona-server-5.1-param/439/

26611

[Sergei Glushchenko (sergei.glushchenko)]

Approve g2

review: Approve (g2)

[Stewart Smith (stewart)]

review: Approve

=== modified file 'Percona-Server/mysql-test/r/percona_innodb_fake_changes.result'
--- Percona-Server/mysql-test/r/percona_innodb_fake_changes.result	2011-11-24 02:00:54 +0000
+++ Percona-Server/mysql-test/r/percona_innodb_fake_changes.result	2012-10-12 12:38:32 +0000
@@ -1,4 +1,4 @@
-DROP TABLE IF EXISTS t1;
+DROP TABLE IF EXISTS t1, t2, t3;
 # Checking variables
 SHOW VARIABLES LIKE 'innodb_fake_changes';
 Variable_name	Value
@@ -36,6 +36,12 @@
 COMMIT;
 ERROR HY000: Got error 131 during COMMIT
 SET innodb_fake_changes=default;
+# Verify that the fake changes to t1 did not leak through
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+should_be_1
+1
 DROP TABLE t1;
 # DDL must result in error
 CREATE TABLE t1 (a INT) ENGINE=InnoDB;
@@ -51,5 +57,19 @@
 ALTER TABLE t1 ENGINE=MyISAM;
 ERROR HY000: Got error 131 during COMMIT
 ROLLBACK;
+SET innodb_fake_changes=0;
+CREATE TABLE t3 (a INT primary key, b text) ENGINE=InnoDB;
+INSERT INTO t3 VALUES (1,'');
+COMMIT;
+SET innodb_fake_changes=1;
+UPDATE t3 set b=lpad('b',11000,'c') where a=1;
+COMMIT;
+ERROR HY000: Got error 131 during COMMIT
 SET innodb_fake_changes=default;
-DROP TABLE t1;
+# Verify that the fake changes to t3 did not leak through
+CHECK TABLE t3;
+Table	Op	Msg_type	Msg_text
+test.t3	check	status	OK
+should_be_1
+1
+DROP TABLE t1, t3;
 
=== modified file 'Percona-Server/mysql-test/t/percona_innodb_fake_changes.test'
--- Percona-Server/mysql-test/t/percona_innodb_fake_changes.test	2011-11-24 02:00:54 +0000
+++ Percona-Server/mysql-test/t/percona_innodb_fake_changes.test	2012-10-12 12:38:32 +0000
@@ -1,7 +1,7 @@
 --source include/have_innodb_plugin.inc
 
 --disable_warnings
-DROP TABLE IF EXISTS t1;
+DROP TABLE IF EXISTS t1, t2, t3;
 --enable_warnings
 
 
@@ -19,6 +19,7 @@
 --echo # DML should be fine
 CREATE TABLE t1 (a INT) ENGINE=InnoDB;
 INSERT INTO t1 VALUES (1);
+let $t1_checksum_1= `CHECKSUM TABLE t1 EXTENDED`;
 SET autocommit=0;
 SET innodb_fake_changes=1;
 BEGIN;
@@ -29,6 +30,12 @@
 --error 1180
 COMMIT;
 SET innodb_fake_changes=default;
+--echo # Verify that the fake changes to t1 did not leak through
+CHECK TABLE t1;
+let $t1_checksum_2= `CHECKSUM TABLE t1 EXTENDED`;
+--disable_query_log
+eval SELECT "$t1_checksum_1" LIKE "$t1_checksum_2" AS should_be_1;
+--enable_query_log
 DROP TABLE t1;
 
 --echo # DDL must result in error
@@ -45,5 +52,24 @@
 --error 1180
 ALTER TABLE t1 ENGINE=MyISAM;
 ROLLBACK;
+
+# Test for bug 890404: uninitialized value warning in btr_cur_pessimistic_update
+SET innodb_fake_changes=0;
+CREATE TABLE t3 (a INT primary key, b text) ENGINE=InnoDB;
+INSERT INTO t3 VALUES (1,'');
+COMMIT;
+let $t3_checksum_1= `CHECKSUM TABLE t3 EXTENDED`;
+SET innodb_fake_changes=1;
+
+UPDATE t3 set b=lpad('b',11000,'c') where a=1;
+--error ER_ERROR_DURING_COMMIT
+COMMIT;
+
 SET innodb_fake_changes=default;
-DROP TABLE t1;
+--echo # Verify that the fake changes to t3 did not leak through
+CHECK TABLE t3;
+let $t3_checksum_2= `CHECKSUM TABLE t3 EXTENDED`;
+--disable_query_log
+eval SELECT "$t3_checksum_1" LIKE "$t3_checksum_2" AS should_be_1;
+--enable_query_log
+DROP TABLE t1, t3;
 
=== modified file 'Percona-Server/storage/innodb_plugin/btr/btr0cur.c'
--- Percona-Server/storage/innodb_plugin/btr/btr0cur.c	2012-08-20 03:14:02 +0000
+++ Percona-Server/storage/innodb_plugin/btr/btr0cur.c	2012-10-12 12:38:32 +0000
@@ -2334,7 +2334,7 @@
 	itself.  Thus the following call is safe. */
 	row_upd_index_replace_new_col_vals_index_pos(new_entry, index, update,
 						     FALSE, *heap);
-	if (!(flags & BTR_KEEP_SYS_FLAG)) {
+	if (!(flags & BTR_KEEP_SYS_FLAG) && !trx->fake_changes) {
 		row_upd_index_entry_sys_field(new_entry, index, DATA_ROLL_PTR,
 					      roll_ptr);
 		row_upd_index_entry_sys_field(new_entry, index, DATA_TRX_ID,