automerge: mysql-5.1-bugteam branch --> mysql-5.1-bugteam latest

NOTE: added TODO to the comments requested by reviewer during this
      merge.

mysql-test/extra/rpl_tests/rpl_set_null.test

+# Both of the following tests check that comparison of binlog BI
+# against SE record will not fail due to remains from previous values
+# in the SE record (before a given field was set to null).
+#
+# In MIXED mode:
+# - Insert and update are executed as statements
+# - Delete is executed as a row event
+# - Assertion: checks that comparison will not fail because the update
+#              statement will clear the record contents for the nulled
+#              field. If data was not cleared, some engines may keep
+#              the value and return it later as garbage - despite the
+#              fact that field is null. This may cause slave to
+#              falsely fail in the comparison (memcmp would fail
+#              because of "garbage" in record data).
+#
+# In ROW mode:
+# - Insert, update and delete are executed as row events.
+# - Assertion: checks that comparison will not fail because the update
+#              rows event will clear the record contents before
+#              feeding the new value to the SE. This protects against
+#              SEs that do not clear record contents when storing
+#              nulled fields. If the engine did not clear the data it
+#              would cause slave to falsely fail in the comparison
+#              (memcmp would fail because of "garbage" in record
+#              data). This scenario is pretty much the same described
+#              above in MIXED mode, but checks different execution
+#              path in the slave.
+
+# BUG#49481: RBR: MyISAM and bit fields may cause slave to stop on
+#  delete cant find record
+
+-- source include/master-slave-reset.inc
+
+-- connection master
+-- eval CREATE TABLE t1 (c1 BIT, c2 INT) Engine=$engine
+INSERT INTO `t1` VALUES ( 1, 1 );
+UPDATE t1 SET c1=NULL where c2=1;
+-- sync_slave_with_master
+
+-- let $diff_table_1=master:test.t1
+-- let $diff_table_2=slave:test.t1
+-- source include/diff_tables.inc
+
+-- connection master
+# triggers switch to row mode when on mixed 
+DELETE FROM t1 WHERE c2=1 LIMIT 1;
+-- sync_slave_with_master
+
+-- let $diff_table_1=master:test.t1
+-- let $diff_table_2=slave:test.t1
+-- source include/diff_tables.inc
+
+-- connection master
+DROP TABLE t1;
+-- sync_slave_with_master
+
+-- source include/master-slave-reset.inc
+
+-- connection master
+
+# BUG#49482: RBR: Replication may break on deletes when MyISAM tables
+#  + char field are used
+
+-- eval CREATE TABLE t1 (c1 CHAR) Engine=$engine
+
+INSERT INTO t1 ( c1 ) VALUES ( 'w' ) ;
+SELECT * FROM t1;
+UPDATE t1 SET c1=NULL WHERE c1='w';
+-- sync_slave_with_master
+
+-- let $diff_table_1=master:test.t1
+-- let $diff_table_2=slave:test.t1
+-- source include/diff_tables.inc
+
+-- connection master
+# triggers switch to row mode when on mixed 
+DELETE FROM t1 LIMIT 2;
+-- sync_slave_with_master
+
+-- let $diff_table_1=master:test.t1
+-- let $diff_table_2=slave:test.t1
+-- source include/diff_tables.inc
+
+-- connection master
+DROP TABLE t1;
+-- sync_slave_with_master

mysql-test/suite/rpl/r/rpl_set_null_innodb.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 BIT, c2 INT) Engine=InnoDB;
+INSERT INTO `t1` VALUES ( 1, 1 );
+UPDATE t1 SET c1=NULL where c2=1;
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 WHERE c2=1 LIMIT 1;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 CHAR) Engine=InnoDB;
+INSERT INTO t1 ( c1 ) VALUES ( 'w' ) ;
+SELECT * FROM t1;
+c1
+w
+UPDATE t1 SET c1=NULL WHERE c1='w';
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 LIMIT 2;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;

mysql-test/suite/rpl/r/rpl_set_null_myisam.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 BIT, c2 INT) Engine=MyISAM;
+INSERT INTO `t1` VALUES ( 1, 1 );
+UPDATE t1 SET c1=NULL where c2=1;
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 WHERE c2=1 LIMIT 1;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 CHAR) Engine=MyISAM;
+INSERT INTO t1 ( c1 ) VALUES ( 'w' ) ;
+SELECT * FROM t1;
+c1
+w
+UPDATE t1 SET c1=NULL WHERE c1='w';
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 LIMIT 2;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;

mysql-test/suite/rpl/t/rpl_set_null_innodb.test

+-- source include/have_binlog_format_mixed_or_row.inc
+-- source include/master-slave.inc
+-- source include/have_innodb.inc
+
+-- let $engine= InnoDB
+-- source extra/rpl_tests/rpl_set_null.test

mysql-test/suite/rpl/t/rpl_set_null_myisam.test

+-- source include/have_binlog_format_mixed_or_row.inc
+-- source include/master-slave.inc
+
+-- let $engine= MyISAM
+-- source extra/rpl_tests/rpl_set_null.test

mysql-test/suite/rpl_ndb/r/rpl_ndb_set_null.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 BIT, c2 INT) Engine=NDB;
+INSERT INTO `t1` VALUES ( 1, 1 );
+UPDATE t1 SET c1=NULL where c2=1;
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 WHERE c2=1 LIMIT 1;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (c1 CHAR) Engine=NDB;
+INSERT INTO t1 ( c1 ) VALUES ( 'w' ) ;
+SELECT * FROM t1;
+c1
+w
+UPDATE t1 SET c1=NULL WHERE c1='w';
+Comparing tables master:test.t1 and slave:test.t1
+DELETE FROM t1 LIMIT 2;
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;

mysql-test/suite/rpl_ndb/t/rpl_ndb_set_null.test

+-- source include/have_ndb.inc
+-- source include/have_binlog_format_mixed_or_row.inc
+-- source include/ndb_master-slave.inc
+
+-- let $engine= NDB
+-- source extra/rpl_tests/rpl_set_null.test

sql/field.h

@@ -1926,7 +1926,12 @@ public:
   uint32 max_display_length() { return field_length; }
   uint size_of() const { return sizeof(*this); }
   Item_result result_type () const { return INT_RESULT; }
-  int reset(void) { bzero(ptr, bytes_in_rec); return 0; }
+  int reset(void) { 
+    bzero(ptr, bytes_in_rec); 
+    if (bit_ptr && (bit_len > 0))  // reset odd bits among null bits
+      clr_rec_bits(bit_ptr, bit_ofs, bit_len);
+    return 0; 
+  }
   int store(const char *to, uint length, CHARSET_INFO *charset);
   int store(double nr);
   int store(longlong nr, bool unsigned_val);

sql/rpl_record.cc

@@ -231,6 +231,22 @@ unpack_row(Relay_log_info const *rli,
         {
           DBUG_PRINT("debug", ("Was NULL; null mask: 0x%x; null bits: 0x%x",
                                null_mask, null_bits));
+          /** 
+            Calling reset just in case one is unpacking on top a 
+            record with data. 
+
+            This could probably go into set_null() but doing so, 
+            (i) triggers assertion in other parts of the code at 
+            the moment; (ii) it would make us reset the field,
+            always when setting null, which right now doesn't seem 
+            needed anywhere else except here.
+
+            TODO: maybe in the future we should consider moving 
+                  the reset to make it part of set_null. But then
+                  the assertions triggered need to be 
+                  addressed/revisited.
+           */
+          f->reset();
           f->set_null();
         }
         else