diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
new file mode 100644
index 0000000000000000000000000000000000000000..e55a4296f2f50677539b2b68ca4c1be91cc76f22
--- /dev/null
+++ b/src/test/regress/expected/xml_2.out
@@ -0,0 +1,915 @@
+CREATE TABLE xmltest (
+ id int,
+ data xml
+);
+INSERT INTO xmltest VALUES (1, '<value>one</value>');
+INSERT INTO xmltest VALUES (2, '<value>two</value>');
+INSERT INTO xmltest VALUES (3, '<wrong');
+ERROR: invalid XML content
+LINE 1: INSERT INTO xmltest VALUES (3, '<wrong');
+ ^
+DETAIL: line 1: Couldn't find end of Start Tag wrong line 1
+SELECT * FROM xmltest;
+ id | data
+----+--------------------
+ 1 | <value>one</value>
+ 2 | <value>two</value>
+(2 rows)
+
+SELECT xmlcomment('test');
+ xmlcomment
+-------------
+ <!--test-->
+(1 row)
+
+SELECT xmlcomment('-test');
+ xmlcomment
+--------------
+ <!---test-->
+(1 row)
+
+SELECT xmlcomment('test-');
+ERROR: invalid XML comment
+SELECT xmlcomment('--test');
+ERROR: invalid XML comment
+SELECT xmlcomment('te st');
+ xmlcomment
+--------------
+ <!--te st-->
+(1 row)
+
+SELECT xmlconcat(xmlcomment('hello'),
+ xmlelement(NAME qux, 'foo'),
+ xmlcomment('world'));
+ xmlconcat
+----------------------------------------
+ <!--hello--><qux>foo</qux><!--world-->
+(1 row)
+
+SELECT xmlconcat('hello', 'you');
+ xmlconcat
+-----------
+ helloyou
+(1 row)
+
+SELECT xmlconcat(1, 2);
+ERROR: argument of XMLCONCAT must be type xml, not type integer
+LINE 1: SELECT xmlconcat(1, 2);
+ ^
+SELECT xmlconcat('bad', '<syntax');
+ERROR: invalid XML content
+LINE 1: SELECT xmlconcat('bad', '<syntax');
+ ^
+DETAIL: line 1: Couldn't find end of Start Tag syntax line 1
+SELECT xmlconcat('<foo/>', NULL, '<?xml version="1.1" standalone="no"?><bar/>');
+ xmlconcat
+--------------
+ <foo/><bar/>
+(1 row)
+
+SELECT xmlconcat('<?xml version="1.1"?><foo/>', NULL, '<?xml version="1.1" standalone="no"?><bar/>');
+ xmlconcat
+-----------------------------------
+ <?xml version="1.1"?><foo/><bar/>
+(1 row)
+
+SELECT xmlconcat(NULL);
+ xmlconcat
+-----------
+
+(1 row)
+
+SELECT xmlconcat(NULL, NULL);
+ xmlconcat
+-----------
+
+(1 row)
+
+SELECT xmlelement(name element,
+ xmlattributes (1 as one, 'deuce' as two),
+ 'content');
+ xmlelement
+------------------------------------------------
+ <element one="1" two="deuce">content</element>
+(1 row)
+
+SELECT xmlelement(name element,
+ xmlattributes ('unnamed and wrong'));
+ERROR: unnamed XML attribute value must be a column reference
+LINE 2: xmlattributes ('unnamed and wrong'));
+ ^
+SELECT xmlelement(name element, xmlelement(name nested, 'stuff'));
+ xmlelement
+-------------------------------------------
+ <element><nested>stuff</nested></element>
+(1 row)
+
+SELECT xmlelement(name employee, xmlforest(name, age, salary as pay)) FROM emp;
+ xmlelement
+----------------------------------------------------------------------
+ <employee><name>sharon</name><age>25</age><pay>1000</pay></employee>
+ <employee><name>sam</name><age>30</age><pay>2000</pay></employee>
+ <employee><name>bill</name><age>20</age><pay>1000</pay></employee>
+ <employee><name>jeff</name><age>23</age><pay>600</pay></employee>
+ <employee><name>cim</name><age>30</age><pay>400</pay></employee>
+ <employee><name>linda</name><age>19</age><pay>100</pay></employee>
+(6 rows)
+
+SELECT xmlelement(name duplicate, xmlattributes(1 as a, 2 as b, 3 as a));
+ERROR: XML attribute name "a" appears more than once
+LINE 1: ...ment(name duplicate, xmlattributes(1 as a, 2 as b, 3 as a));
+ ^
+SELECT xmlelement(name num, 37);
+ xmlelement
+---------------
+ <num>37</num>
+(1 row)
+
+SELECT xmlelement(name foo, text 'bar');
+ xmlelement
+----------------
+ <foo>bar</foo>
+(1 row)
+
+SELECT xmlelement(name foo, xml 'bar');
+ xmlelement
+----------------
+ <foo>bar</foo>
+(1 row)
+
+SELECT xmlelement(name foo, text 'b<a/>r');
+ xmlelement
+-------------------------
+ <foo>b<a/>r</foo>
+(1 row)
+
+SELECT xmlelement(name foo, xml 'b<a/>r');
+ xmlelement
+-------------------
+ <foo>b<a/>r</foo>
+(1 row)
+
+SELECT xmlelement(name foo, array[1, 2, 3]);
+ xmlelement
+-------------------------------------------------------------------------
+ <foo><element>1</element><element>2</element><element>3</element></foo>
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlelement(name foo, bytea 'bar');
+ xmlelement
+-----------------
+ <foo>YmFy</foo>
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlelement(name foo, bytea 'bar');
+ xmlelement
+-------------------
+ <foo>626172</foo>
+(1 row)
+
+SELECT xmlelement(name foo, xmlattributes(true as bar));
+ xmlelement
+-------------------
+ <foo bar="true"/>
+(1 row)
+
+SELECT xmlelement(name foo, xmlattributes('2009-04-09 00:24:37'::timestamp as bar));
+ xmlelement
+----------------------------------
+ <foo bar="2009-04-09T00:24:37"/>
+(1 row)
+
+SELECT xmlelement(name foo, xmlattributes('infinity'::timestamp as bar));
+ERROR: timestamp out of range
+DETAIL: XML does not support infinite timestamp values.
+SELECT xmlelement(name foo, xmlattributes('<>&"''' as funny, xml 'b<a/>r' as funnier));
+ xmlelement
+------------------------------------------------------------
+ <foo funny="<>&"'" funnier="b<a/>r"/>
+(1 row)
+
+SELECT xmlparse(content 'abc');
+ xmlparse
+----------
+ abc
+(1 row)
+
+SELECT xmlparse(content '<abc>x</abc>');
+ xmlparse
+--------------
+ <abc>x</abc>
+(1 row)
+
+SELECT xmlparse(content '<invalidentity>&</invalidentity>');
+ERROR: invalid XML content
+DETAIL: line 1: xmlParseEntityRef: no name
+<invalidentity>&</invalidentity>
+ ^
+line 1: chunk is not well balanced
+SELECT xmlparse(content '<undefinedentity>&idontexist;</undefinedentity>');
+ERROR: invalid XML content
+DETAIL: line 1: Entity 'idontexist' not defined
+<undefinedentity>&idontexist;</undefinedentity>
+ ^
+line 1: chunk is not well balanced
+SELECT xmlparse(content '<invalidns xmlns=''<''/>');
+ xmlparse
+---------------------------
+ <invalidns xmlns='<'/>
+(1 row)
+
+SELECT xmlparse(content '<relativens xmlns=''relative''/>');
+ xmlparse
+--------------------------------
+ <relativens xmlns='relative'/>
+(1 row)
+
+SELECT xmlparse(content '<twoerrors>&idontexist;</unbalanced>');
+ERROR: invalid XML content
+DETAIL: line 1: Entity 'idontexist' not defined
+<twoerrors>&idontexist;</unbalanced>
+ ^
+line 1: Opening and ending tag mismatch: twoerrors line 1 and unbalanced
+line 1: chunk is not well balanced
+SELECT xmlparse(content '<nosuchprefix:tag/>');
+ xmlparse
+---------------------
+ <nosuchprefix:tag/>
+(1 row)
+
+SELECT xmlparse(document 'abc');
+ERROR: invalid XML document
+DETAIL: line 1: Start tag expected, '<' not found
+abc
+^
+SELECT xmlparse(document '<abc>x</abc>');
+ xmlparse
+--------------
+ <abc>x</abc>
+(1 row)
+
+SELECT xmlparse(document '<invalidentity>&</abc>');
+ERROR: invalid XML document
+DETAIL: line 1: xmlParseEntityRef: no name
+<invalidentity>&</abc>
+ ^
+line 1: Opening and ending tag mismatch: invalidentity line 1 and abc
+SELECT xmlparse(document '<undefinedentity>&idontexist;</abc>');
+ERROR: invalid XML document
+DETAIL: line 1: Entity 'idontexist' not defined
+<undefinedentity>&idontexist;</abc>
+ ^
+line 1: Opening and ending tag mismatch: undefinedentity line 1 and abc
+SELECT xmlparse(document '<invalidns xmlns=''<''/>');
+ xmlparse
+---------------------------
+ <invalidns xmlns='<'/>
+(1 row)
+
+SELECT xmlparse(document '<relativens xmlns=''relative''/>');
+ xmlparse
+--------------------------------
+ <relativens xmlns='relative'/>
+(1 row)
+
+SELECT xmlparse(document '<twoerrors>&idontexist;</unbalanced>');
+ERROR: invalid XML document
+DETAIL: line 1: Entity 'idontexist' not defined
+<twoerrors>&idontexist;</unbalanced>
+ ^
+line 1: Opening and ending tag mismatch: twoerrors line 1 and unbalanced
+SELECT xmlparse(document '<nosuchprefix:tag/>');
+ xmlparse
+---------------------
+ <nosuchprefix:tag/>
+(1 row)
+
+SELECT xmlpi(name foo);
+ xmlpi
+---------
+ <?foo?>
+(1 row)
+
+SELECT xmlpi(name xml);
+ERROR: invalid XML processing instruction
+DETAIL: XML processing instruction target name cannot be "xml".
+SELECT xmlpi(name xmlstuff);
+ xmlpi
+--------------
+ <?xmlstuff?>
+(1 row)
+
+SELECT xmlpi(name foo, 'bar');
+ xmlpi
+-------------
+ <?foo bar?>
+(1 row)
+
+SELECT xmlpi(name foo, 'in?>valid');
+ERROR: invalid XML processing instruction
+DETAIL: XML processing instruction cannot contain "?>".
+SELECT xmlpi(name foo, null);
+ xmlpi
+-------
+
+(1 row)
+
+SELECT xmlpi(name xml, null);
+ERROR: invalid XML processing instruction
+DETAIL: XML processing instruction target name cannot be "xml".
+SELECT xmlpi(name xmlstuff, null);
+ xmlpi
+-------
+
+(1 row)
+
+SELECT xmlpi(name "xml-stylesheet", 'href="mystyle.css" type="text/css"');
+ xmlpi
+-------------------------------------------------------
+ <?xml-stylesheet href="mystyle.css" type="text/css"?>
+(1 row)
+
+SELECT xmlpi(name foo, ' bar');
+ xmlpi
+-------------
+ <?foo bar?>
+(1 row)
+
+SELECT xmlroot(xml '<foo/>', version no value, standalone no value);
+ xmlroot
+---------
+ <foo/>
+(1 row)
+
+SELECT xmlroot(xml '<foo/>', version '2.0');
+ xmlroot
+-----------------------------
+ <?xml version="2.0"?><foo/>
+(1 row)
+
+SELECT xmlroot(xml '<foo/>', version no value, standalone yes);
+ xmlroot
+----------------------------------------------
+ <?xml version="1.0" standalone="yes"?><foo/>
+(1 row)
+
+SELECT xmlroot(xml '<?xml version="1.1"?><foo/>', version no value, standalone yes);
+ xmlroot
+----------------------------------------------
+ <?xml version="1.0" standalone="yes"?><foo/>
+(1 row)
+
+SELECT xmlroot(xmlroot(xml '<foo/>', version '1.0'), version '1.1', standalone no);
+ xmlroot
+---------------------------------------------
+ <?xml version="1.1" standalone="no"?><foo/>
+(1 row)
+
+SELECT xmlroot('<?xml version="1.1" standalone="yes"?><foo/>', version no value, standalone no);
+ xmlroot
+---------------------------------------------
+ <?xml version="1.0" standalone="no"?><foo/>
+(1 row)
+
+SELECT xmlroot('<?xml version="1.1" standalone="yes"?><foo/>', version no value, standalone no value);
+ xmlroot
+---------
+ <foo/>
+(1 row)
+
+SELECT xmlroot('<?xml version="1.1" standalone="yes"?><foo/>', version no value);
+ xmlroot
+----------------------------------------------
+ <?xml version="1.0" standalone="yes"?><foo/>
+(1 row)
+
+SELECT xmlroot (
+ xmlelement (
+ name gazonk,
+ xmlattributes (
+ 'val' AS name,
+ 1 + 1 AS num
+ ),
+ xmlelement (
+ NAME qux,
+ 'foo'
+ )
+ ),
+ version '1.0',
+ standalone yes
+);
+ xmlroot
+------------------------------------------------------------------------------------------
+ <?xml version="1.0" standalone="yes"?><gazonk name="val" num="2"><qux>foo</qux></gazonk>
+(1 row)
+
+SELECT xmlserialize(content data as character varying(20)) FROM xmltest;
+ xmlserialize
+--------------------
+ <value>one</value>
+ <value>two</value>
+(2 rows)
+
+SELECT xmlserialize(content 'good' as char(10));
+ xmlserialize
+--------------
+ good
+(1 row)
+
+SELECT xmlserialize(document 'bad' as text);
+ERROR: not an XML document
+SELECT xml '<foo>bar</foo>' IS DOCUMENT;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT xml '<foo>bar</foo><bar>foo</bar>' IS DOCUMENT;
+ ?column?
+----------
+ f
+(1 row)
+
+SELECT xml '<abc/>' IS NOT DOCUMENT;
+ ?column?
+----------
+ f
+(1 row)
+
+SELECT xml 'abc' IS NOT DOCUMENT;
+ ?column?
+----------
+ t
+(1 row)
+
+SELECT '<>' IS NOT DOCUMENT;
+ERROR: invalid XML content
+LINE 1: SELECT '<>' IS NOT DOCUMENT;
+ ^
+DETAIL: line 1: StartTag: invalid element name
+<>
+ ^
+SELECT xmlagg(data) FROM xmltest;
+ xmlagg
+--------------------------------------
+ <value>one</value><value>two</value>
+(1 row)
+
+SELECT xmlagg(data) FROM xmltest WHERE id > 10;
+ xmlagg
+--------
+
+(1 row)
+
+SELECT xmlelement(name employees, xmlagg(xmlelement(name name, name))) FROM emp;
+ xmlelement
+--------------------------------------------------------------------------------------------------------------------------------
+ <employees><name>sharon</name><name>sam</name><name>bill</name><name>jeff</name><name>cim</name><name>linda</name></employees>
+(1 row)
+
+-- Check mapping SQL identifier to XML name
+SELECT xmlpi(name ":::_xml_abc135.%-&_");
+ xmlpi
+-------------------------------------------------
+ <?_x003A_::_x005F_xml_abc135._x0025_-_x0026__?>
+(1 row)
+
+SELECT xmlpi(name "123");
+ xmlpi
+---------------
+ <?_x0031_23?>
+(1 row)
+
+PREPARE foo (xml) AS SELECT xmlconcat('<foo/>', $1);
+SET XML OPTION DOCUMENT;
+EXECUTE foo ('<bar/>');
+ xmlconcat
+--------------
+ <foo/><bar/>
+(1 row)
+
+EXECUTE foo ('bad');
+ERROR: invalid XML document
+LINE 1: EXECUTE foo ('bad');
+ ^
+DETAIL: line 1: Start tag expected, '<' not found
+bad
+^
+SET XML OPTION CONTENT;
+EXECUTE foo ('<bar/>');
+ xmlconcat
+--------------
+ <foo/><bar/>
+(1 row)
+
+EXECUTE foo ('good');
+ xmlconcat
+------------
+ <foo/>good
+(1 row)
+
+-- Test backwards parsing
+CREATE VIEW xmlview1 AS SELECT xmlcomment('test');
+CREATE VIEW xmlview2 AS SELECT xmlconcat('hello', 'you');
+CREATE VIEW xmlview3 AS SELECT xmlelement(name element, xmlattributes (1 as ":one:", 'deuce' as two), 'content&');
+CREATE VIEW xmlview4 AS SELECT xmlelement(name employee, xmlforest(name, age, salary as pay)) FROM emp;
+CREATE VIEW xmlview5 AS SELECT xmlparse(content '<abc>x</abc>');
+CREATE VIEW xmlview6 AS SELECT xmlpi(name foo, 'bar');
+CREATE VIEW xmlview7 AS SELECT xmlroot(xml '<foo/>', version no value, standalone yes);
+CREATE VIEW xmlview8 AS SELECT xmlserialize(content 'good' as char(10));
+CREATE VIEW xmlview9 AS SELECT xmlserialize(content 'good' as text);
+SELECT table_name, view_definition FROM information_schema.views
+ WHERE table_name LIKE 'xmlview%' ORDER BY 1;
+ table_name | view_definition
+------------+----------------------------------------------------------------------------------------------------------------------------
+ xmlview1 | SELECT xmlcomment('test'::text) AS xmlcomment;
+ xmlview2 | SELECT XMLCONCAT('hello'::xml, 'you'::xml) AS "xmlconcat";
+ xmlview3 | SELECT XMLELEMENT(NAME element, XMLATTRIBUTES(1 AS ":one:", 'deuce' AS two), 'content&') AS "xmlelement";
+ xmlview4 | SELECT XMLELEMENT(NAME employee, XMLFOREST(emp.name AS name, emp.age AS age, emp.salary AS pay)) AS "xmlelement" FROM emp;
+ xmlview5 | SELECT XMLPARSE(CONTENT '<abc>x</abc>'::text STRIP WHITESPACE) AS "xmlparse";
+ xmlview6 | SELECT XMLPI(NAME foo, 'bar'::text) AS "xmlpi";
+ xmlview7 | SELECT XMLROOT('<foo/>'::xml, VERSION NO VALUE, STANDALONE YES) AS "xmlroot";
+ xmlview8 | SELECT (XMLSERIALIZE(CONTENT 'good'::xml AS character(10)))::character(10) AS "xmlserialize";
+ xmlview9 | SELECT XMLSERIALIZE(CONTENT 'good'::xml AS text) AS "xmlserialize";
+(9 rows)
+
+-- Text XPath expressions evaluation
+SELECT xpath('/value', data) FROM xmltest;
+ xpath
+----------------------
+ {<value>one</value>}
+ {<value>two</value>}
+(2 rows)
+
+SELECT xpath(NULL, NULL) IS NULL FROM xmltest;
+ ?column?
+----------
+ t
+ t
+(2 rows)
+
+SELECT xpath('', '<!-- error -->');
+ERROR: empty XPath expression
+CONTEXT: SQL function "xpath" statement 1
+SELECT xpath('//text()', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>');
+ xpath
+----------------
+ {"number one"}
+(1 row)
+
+SELECT xpath('//loc:piece/@id', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>', ARRAY[ARRAY['loc', 'http://127.0.0.1']]);
+ xpath
+-------
+ {1,2}
+(1 row)
+
+SELECT xpath('//loc:piece', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>', ARRAY[ARRAY['loc', 'http://127.0.0.1']]);
+ xpath
+------------------------------------------------------------------------------------------------------------------------------------------------
+ {"<local:piece xmlns:local=\"http://127.0.0.1\" id=\"1\">number one</local:piece>","<local:piece xmlns:local=\"http://127.0.0.1\" id=\"2\"/>"}
+(1 row)
+
+SELECT xpath('//loc:piece', '<local:data xmlns:local="http://127.0.0.1" xmlns="http://127.0.0.2"><local:piece id="1"><internal>number one</internal><internal2/></local:piece><local:piece id="2" /></local:data>', ARRAY[ARRAY['loc', 'http://127.0.0.1']]);
+ xpath
+--------------------------------------------------------------------------------------
+ {"<local:piece xmlns:local=\"http://127.0.0.1\" xmlns=\"http://127.0.0.2\" id=\"1\">+
+ <internal>number one</internal> +
+ <internal2/> +
+ </local:piece>","<local:piece xmlns:local=\"http://127.0.0.1\" id=\"2\"/>"}
+(1 row)
+
+SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
+ xpath
+-------------------------
+ {<b>two</b>,<b>etc</b>}
+(1 row)
+
+SELECT xpath('//text()', '<root><</root>');
+ xpath
+--------
+ {<}
+(1 row)
+
+SELECT xpath('//@value', '<root value="<"/>');
+ xpath
+--------
+ {<}
+(1 row)
+
+SELECT xpath('''<<invalid>>''', '<root/>');
+ xpath
+---------------------------
+ {<<invalid>>}
+(1 row)
+
+SELECT xpath('count(//*)', '<root><sub/><sub/></root>');
+ xpath
+-------
+ {3}
+(1 row)
+
+SELECT xpath('count(//*)=0', '<root><sub/><sub/></root>');
+ xpath
+---------
+ {false}
+(1 row)
+
+SELECT xpath('count(//*)=3', '<root><sub/><sub/></root>');
+ xpath
+--------
+ {true}
+(1 row)
+
+SELECT xpath('name(/*)', '<root><sub/><sub/></root>');
+ xpath
+--------
+ {root}
+(1 row)
+
+SELECT xpath('/nosuchtag', '<root/>');
+ xpath
+-------
+ {}
+(1 row)
+
+-- Test xmlexists and xpath_exists
+SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
+ xmlexists
+-----------
+ f
+(1 row)
+
+SELECT xmlexists('//town[text() = ''Cwmbran'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
+ xmlexists
+-----------
+ t
+(1 row)
+
+SELECT xmlexists('count(/nosuchtag)' PASSING BY REF '<root/>');
+ xmlexists
+-----------
+ t
+(1 row)
+
+SELECT xpath_exists('//town[text() = ''Toronto'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ xpath_exists
+--------------
+ f
+(1 row)
+
+SELECT xpath_exists('//town[text() = ''Cwmbran'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ xpath_exists
+--------------
+ t
+(1 row)
+
+SELECT xpath_exists('count(/nosuchtag)', '<root/>'::xml);
+ xpath_exists
+--------------
+ t
+(1 row)
+
+INSERT INTO xmltest VALUES (4, '<menu><beers><name>Budvar</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
+INSERT INTO xmltest VALUES (5, '<menu><beers><name>Molson</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
+INSERT INTO xmltest VALUES (6, '<myns:menu xmlns:myns="http://myns.com"><myns:beers><myns:name>Budvar</myns:name><myns:cost>free</myns:cost><myns:name>Carling</myns:name><myns:cost>lots</myns:cost></myns:beers></myns:menu>'::xml);
+INSERT INTO xmltest VALUES (7, '<myns:menu xmlns:myns="http://myns.com"><myns:beers><myns:name>Molson</myns:name><myns:cost>free</myns:cost><myns:name>Carling</myns:name><myns:cost>lots</myns:cost></myns:beers></myns:menu>'::xml);
+SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beer' PASSING data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beer' PASSING BY REF data BY REF);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers' PASSING BY REF data);
+ count
+-------
+ 2
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers/name[text() = ''Molson'']' PASSING BY REF data);
+ count
+-------
+ 1
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beer',data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers',data);
+ count
+-------
+ 2
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers/name[text() = ''Molson'']',data);
+ count
+-------
+ 1
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beer',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 2
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers/myns:name[text() = ''Molson'']',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 1
+(1 row)
+
+CREATE TABLE query ( expr TEXT );
+INSERT INTO query VALUES ('/menu/beers/cost[text() = ''lots'']');
+SELECT COUNT(id) FROM xmltest, query WHERE xmlexists(expr PASSING BY REF data);
+ count
+-------
+ 2
+(1 row)
+
+-- Test xml_is_well_formed and variants
+SELECT xml_is_well_formed_document('<foo>bar</foo>');
+ xml_is_well_formed_document
+-----------------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed_document('abc');
+ xml_is_well_formed_document
+-----------------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed_content('<foo>bar</foo>');
+ xml_is_well_formed_content
+----------------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed_content('abc');
+ xml_is_well_formed_content
+----------------------------
+ t
+(1 row)
+
+SET xmloption TO DOCUMENT;
+SELECT xml_is_well_formed('abc');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<abc/>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<foo>bar</foo>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<foo>bar</foo');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<foo><bar>baz</foo>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<pg:foo xmlns:pg="http://postgresql.org/stuff">bar</my:foo>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<pg:foo xmlns:pg="http://postgresql.org/stuff">bar</pg:foo>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<invalidentity>&</abc>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<undefinedentity>&idontexist;</abc>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SELECT xml_is_well_formed('<invalidns xmlns=''<''/>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<relativens xmlns=''relative''/>');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+SELECT xml_is_well_formed('<twoerrors>&idontexist;</unbalanced>');
+ xml_is_well_formed
+--------------------
+ f
+(1 row)
+
+SET xmloption TO CONTENT;
+SELECT xml_is_well_formed('abc');
+ xml_is_well_formed
+--------------------
+ t
+(1 row)
+
+-- Since xpath() deals with namespaces, it's a bit stricter about
+-- what's well-formed and what's not. If we don't obey these rules
+-- (i.e. ignore namespace-related errors from libxml), xpath()
+-- fails in subtle ways. The following would for example produce
+-- the xml value
+-- <invalidns xmlns='<'/>
+-- which is invalid because '<' may not appear un-escaped in
+-- attribute values.
+-- Since different libxml versions emit slightly different
+-- error messages, we suppress the DETAIL in this test.
+\set VERBOSITY terse
+SELECT xpath('/*', '<invalidns xmlns=''<''/>');
+ERROR: could not parse XML document
+\set VERBOSITY default
+-- Again, the XML isn't well-formed for namespace purposes
+SELECT xpath('/*', '<nosuchprefix:tag/>');
+ERROR: could not parse XML document
+DETAIL: line 1: Namespace prefix nosuchprefix on tag is not defined
+<nosuchprefix:tag/>
+ ^
+CONTEXT: SQL function "xpath" statement 1
+-- XPath deprecates relative namespaces, but they're not supposed to
+-- throw an error, only a warning.
+SELECT xpath('/*', '<relativens xmlns=''relative''/>');
+WARNING: line 1: xmlns: URI relative is not absolute
+<relativens xmlns='relative'/>
+ ^
+CONTEXT: SQL function "xpath" statement 1
+ xpath
+--------------------------------------
+ {"<relativens xmlns=\"relative\"/>"}
+(1 row)
+
+-- External entity references should not leak filesystem information.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>');
+ xmlparse
+-----------------------------------------------------------------
+ <!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>
+(1 row)
+
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>');
+ xmlparse
+-----------------------------------------------------------------------
+ <!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>
+(1 row)
+
+-- This might or might not load the requested DTD, but it mustn't throw error.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter> </chapter>');
+ xmlparse
+------------------------------------------------------------------------------------------------------------------------------------------------------
+ <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter> </chapter>
+(1 row)
+