Fix for bug #22364 "Inconsistent "matched rows" when executing UPDATE"

In multi_update::send_data(), the counter of matched rows was not correctly incremented, when during insertion of a new row to a temporay table it had to be converted from HEAP to MyISAM.

This fix changes the logic to increment the counter of matched rows in the following cases:
1. If the error returned from write_row() is zero.
2. If the error returned from write_row() is non-zero, is neither HA_ERR_FOUND_DUPP_KEY nor HA_ERR_FOUND_DUPP_UNIQUE, and a call to create_myisam_from_heap() succeeds. 

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/r/update.result

@@ -457,3 +457,38 @@ a	quux
 2	0.100000000000000000000000000000
 3	NULL
 DROP TABLE t1;
+set tmp_table_size=1024;
+create table t1 (id int, a int, key idx(a));
+create table t2 (id int unsigned not null auto_increment primary key, a int);
+insert into t2(a) values(1),(2),(3),(4),(5),(6),(7),(8);
+insert into t2(a) select a from t2;
+insert into t2(a) select a from t2;
+insert into t2(a) select a from t2;
+update t2 set a=id;
+insert into t1 select * from t2;
+select count(*) from t1 join t2 on (t1.a=t2.a);
+count(*)
+64
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+affected rows: 0
+info: Rows matched: 64  Changed: 0  Warnings: 0
+insert into t2(a) select a from t2;
+update t2 set a=id;
+truncate t1;
+insert into t1 select * from t2;
+select count(*) from t1 join t2 on (t1.a=t2.a);
+count(*)
+128
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+affected rows: 0
+info: Rows matched: 128  Changed: 0  Warnings: 0
+update t1 set a=1;
+update t2 set a=1;
+select count(*) from t1 join t2 on (t1.a=t2.a);
+count(*)
+16384
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+affected rows: 127
+info: Rows matched: 128  Changed: 127  Warnings: 0
+drop table t1,t2;
+End of 5.0 tests

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

mysql-test/t/update.test

@@ -376,3 +376,58 @@ INSERT INTO t1( a )
 SELECT * FROM t1;
 
 DROP TABLE t1;
+
+#
+# Bug #22364: Inconsistent "matched rows" when executing UPDATE
+#
+
+connect (con1,localhost,root,,test);
+connection con1;
+
+set tmp_table_size=1024;
+
+# Create the test tables
+create table t1 (id int, a int, key idx(a));
+create table t2 (id int unsigned not null auto_increment primary key, a int);
+insert into t2(a) values(1),(2),(3),(4),(5),(6),(7),(8);
+insert into t2(a) select a from t2; 
+insert into t2(a) select a from t2;
+insert into t2(a) select a from t2; 
+update t2 set a=id;
+insert into t1 select * from t2;
+
+# Check that the number of matched rows is correct when the temporary
+# table is small enough to not be converted to MyISAM
+select count(*) from t1 join t2 on (t1.a=t2.a);
+--enable_info
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+--disable_info
+
+# Increase table sizes
+insert into t2(a) select a from t2; 
+update t2 set a=id; 
+truncate t1; 
+insert into t1 select * from t2; 
+
+# Check that the number of matched rows is correct when the temporary
+# table has to be converted to MyISAM
+select count(*) from t1 join t2 on (t1.a=t2.a);
+--enable_info
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+--disable_info
+
+# Check that the number of matched rows is correct when there are duplicate
+# key errors
+update t1 set a=1;
+update t2 set a=1;
+select count(*) from t1 join t2 on (t1.a=t2.a);
+--enable_info
+update t1 join t2 on (t1.a=t2.a) set t1.id=t2.id;
+--disable_info
+
+drop table t1,t2;
+
+connection default;
+disconnect con1;
+
+--echo End of 5.0 tests

sql/sql_update.cc

@@ -1328,21 +1328,20 @@ bool multi_update::send_data(List<Item> &not_used_values)
       memcpy((char*) tmp_table->field[0]->ptr,
 	     (char*) table->file->ref, table->file->ref_length);
       /* Write row, ignoring duplicated updates to a row */
-      if ((error= tmp_table->file->write_row(tmp_table->record[0])))
+      error= tmp_table->file->write_row(tmp_table->record[0]);
+      if (error != HA_ERR_FOUND_DUPP_KEY && error != HA_ERR_FOUND_DUPP_UNIQUE)
       {
-        if (error != HA_ERR_FOUND_DUPP_KEY &&
-            error != HA_ERR_FOUND_DUPP_UNIQUE &&
+        if (error &&
             create_myisam_from_heap(thd, tmp_table,
                                     tmp_table_param + offset, error, 1))
         {
-	  do_update=0;
+          do_update= 0;
           DBUG_RETURN(1);			// Not a table_is_full error
         }
-      }
-      else
         found++;
       }
     }
+  }
   DBUG_RETURN(0);
 }