bug#27608 XML output is not well-formed

Problem: output was empty if the result is empty.
Fix: print XML header and footer, even if the result
is empty, to produce well-formed XML output.

client/mysql.cc

@@ -2117,6 +2117,17 @@ com_go(String *buffer,char *line __attribute__((unused)))
       if (!mysql_num_rows(result) && ! quick && !info_flag)
       {
 	strmov(buff, "Empty set");
+        if (opt_xml)
+        { 
+          /*
+            We must print XML header and footer
+            to produce a well-formed XML even if
+            the result set is empty (Bug#27608).
+          */
+          init_pager();
+          print_table_data_xml(result);
+          end_pager();
+        }
       }
       else
       {

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/client_xml.result

@@ -71,4 +71,18 @@ insert into t1 values (1, 2, 'a&b a<b a>b');
 	<field name="NULL" xsi:nil="true" />
   </row>
 </resultset>
+<?xml version="1.0"?>
+
+<resultset statement="select 1 limit 0
+" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></resultset>
+--------------
+select 1 limit 0
+--------------
+
+<?xml version="1.0"?>
+
+<resultset statement="select 1 limit 0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></resultset>
+Empty set
+
+Bye
 drop table t1;

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/client_xml.test

@@ -17,5 +17,7 @@ insert into t1 values (1, 2, 'a&b a<b a>b');
 --exec $MYSQL --xml test -e "select 1 > 2 from dual"
 --exec $MYSQL --xml test -e "select 1 & 3 from dual"
 --exec $MYSQL --xml test -e "select null from dual"
+--exec $MYSQL --xml test -e "select 1 limit 0"
+--exec $MYSQL --xml test -vv -e "select 1 limit 0"
 
 drop table t1;