Adding upstream version 16.2.upstream/16.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

11 files changed, 1702 insertions, 0 deletions

diff --git a/contrib/xml2/.gitignore b/contrib/xml2/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/contrib/xml2/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/contrib/xml2/Makefile b/contrib/xml2/Makefile
new file mode 100644
index 0000000..0d703fe
--- /dev/null
+++ b/contrib/xml2/Makefile
@@ -0,0 +1,26 @@
+# contrib/xml2/Makefile
+
+MODULE_big = pgxml
+OBJS = \
+	$(WIN32RES) \
+	xpath.o \
+	xslt_proc.o
+
+EXTENSION = xml2
+DATA = xml2--1.1.sql xml2--1.0--1.1.sql
+PGFILEDESC = "xml2 - XPath querying and XSLT"
+
+REGRESS = xml2
+
+SHLIB_LINK += $(filter -lxslt, $(LIBS)) -lxml2
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/xml2
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/contrib/xml2/expected/xml2.out b/contrib/xml2/expected/xml2.out
new file mode 100644
index 0000000..eba6ae6
--- /dev/null
+++ b/contrib/xml2/expected/xml2.out
@@ -0,0 +1,224 @@
+CREATE EXTENSION xml2;
+select query_to_xml('select 1 as x',true,false,'');
+                         query_to_xml                          
+---------------------------------------------------------------
+ <table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">+
+                                                              +
+ <row>                                                        +
+   <x>1</x>                                                   +
+ </row>                                                       +
+                                                              +
+ </table>                                                     +
+ 
+(1 row)
+
+select xslt_process( query_to_xml('select x from generate_series(1,5) as
+x',true,false,'')::text,
+$$<xsl:stylesheet version="1.0"
+               xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:output method="xml" indent="yes" />
+<xsl:template match="*">
+  <xsl:copy>
+     <xsl:copy-of select="@*" />
+     <xsl:apply-templates />
+  </xsl:copy>
+</xsl:template>
+<xsl:template match="comment()|processing-instruction()">
+  <xsl:copy />
+</xsl:template>
+</xsl:stylesheet>
+$$::text);
+                         xslt_process                          
+---------------------------------------------------------------
+ <?xml version="1.0"?>                                        +
+ <table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">+
+                                                              +
+ <row>                                                        +
+   <x>1</x>                                                   +
+ </row>                                                       +
+                                                              +
+ <row>                                                        +
+   <x>2</x>                                                   +
+ </row>                                                       +
+                                                              +
+ <row>                                                        +
+   <x>3</x>                                                   +
+ </row>                                                       +
+                                                              +
+ <row>                                                        +
+   <x>4</x>                                                   +
+ </row>                                                       +
+                                                              +
+ <row>                                                        +
+   <x>5</x>                                                   +
+ </row>                                                       +
+                                                              +
+ </table>                                                     +
+ 
+(1 row)
+
+CREATE TABLE xpath_test (id integer NOT NULL, t xml);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+ id 
+----
+(0 rows)
+
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+ id | doc 
+----+-----
+  1 |   1
+(1 row)
+
+DROP TABLE xpath_test;
+CREATE TABLE xpath_test (id integer NOT NULL, t text);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+ id 
+----
+(0 rows)
+
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+ id | doc 
+----+-----
+  1 |   1
+(1 row)
+
+create table articles (article_id integer, article_xml xml, date_entered date);
+insert into articles (article_id, article_xml, date_entered)
+values (2, '<article><author>test</author><pages>37</pages></article>', now());
+SELECT * FROM
+xpath_table('article_id',
+            'article_xml',
+            'articles',
+            '/article/author|/article/pages|/article/title',
+            'date_entered > ''2003-01-01'' ')
+AS t(article_id integer, author text, page_count integer, title text);
+ article_id | author | page_count | title 
+------------+--------+------------+-------
+          2 | test   |         37 | 
+(1 row)
+
+-- this used to fail when invoked a second time
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+ xslt_process 
+--------------
+ <aaa/>      +
+ 
+(1 row)
+
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+ xslt_process 
+--------------
+ <aaa/>      +
+ 
+(1 row)
+
+create table t1 (id integer, xml_data xml);
+insert into t1 (id, xml_data)
+values
+(1, '<attributes><attribute name="attr_1">Some
+Value</attribute></attributes>');
+create index idx_xpath on t1 ( xpath_string
+('/attributes/attribute[@name="attr_1"]/text()', xml_data::text));
+SELECT xslt_process('<employee><name>cim</name><age>30</age><pay>400</pay></employee>'::text, $$<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
+  <xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
+  <xsl:strip-space elements="*"/>
+  <xsl:param name="n1"/>
+  <xsl:param name="n2"/>
+  <xsl:param name="n3"/>
+  <xsl:param name="n4"/>
+  <xsl:param name="n5" select="'me'"/>
+  <xsl:template match="*">
+    <xsl:element name="samples">
+      <xsl:element name="sample">
+        <xsl:value-of select="$n1"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n2"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n3"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n4"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n5"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n6"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n7"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n8"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n9"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n10"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n11"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n12"/>
+      </xsl:element>
+    </xsl:element>
+  </xsl:template>
+</xsl:stylesheet>$$::text, 'n1="v1",n2="v2",n3="v3",n4="v4",n5="v5",n6="v6",n7="v7",n8="v8",n9="v9",n10="v10",n11="v11",n12="v12"'::text);
+      xslt_process      
+------------------------
+ <samples>             +
+   <sample>v1</sample> +
+   <sample>v2</sample> +
+   <sample>v3</sample> +
+   <sample>v4</sample> +
+   <sample>v5</sample> +
+   <sample>v6</sample> +
+   <sample>v7</sample> +
+   <sample>v8</sample> +
+   <sample>v9</sample> +
+   <sample>v10</sample>+
+   <sample>v11</sample>+
+   <sample>v12</sample>+
+ </samples>            +
+ 
+(1 row)
+
+-- possible security exploit
+SELECT xslt_process('<xml><foo>Hello from XML</foo></xml>',
+$$<xsl:stylesheet version="1.0"
+      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+      xmlns:sax="http://icl.com/saxon"
+      extension-element-prefixes="sax">
+
+  <xsl:template match="//foo">
+    <sax:output href="0wn3d.txt" method="text">
+      <xsl:value-of select="'0wn3d via xml2 extension and libxslt'"/>
+      <xsl:apply-templates/>
+    </sax:output>
+  </xsl:template>
+</xsl:stylesheet>$$);
+ERROR:  failed to apply stylesheet
diff --git a/contrib/xml2/expected/xml2_1.out b/contrib/xml2/expected/xml2_1.out
new file mode 100644
index 0000000..bac90e5
--- /dev/null
+++ b/contrib/xml2/expected/xml2_1.out
@@ -0,0 +1,168 @@
+CREATE EXTENSION xml2;
+select query_to_xml('select 1 as x',true,false,'');
+                         query_to_xml                          
+---------------------------------------------------------------
+ <table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">+
+                                                              +
+ <row>                                                        +
+   <x>1</x>                                                   +
+ </row>                                                       +
+                                                              +
+ </table>                                                     +
+ 
+(1 row)
+
+select xslt_process( query_to_xml('select x from generate_series(1,5) as
+x',true,false,'')::text,
+$$<xsl:stylesheet version="1.0"
+               xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:output method="xml" indent="yes" />
+<xsl:template match="*">
+  <xsl:copy>
+     <xsl:copy-of select="@*" />
+     <xsl:apply-templates />
+  </xsl:copy>
+</xsl:template>
+<xsl:template match="comment()|processing-instruction()">
+  <xsl:copy />
+</xsl:template>
+</xsl:stylesheet>
+$$::text);
+ERROR:  xslt_process() is not available without libxslt
+CREATE TABLE xpath_test (id integer NOT NULL, t xml);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+ id 
+----
+(0 rows)
+
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+ id | doc 
+----+-----
+  1 |   1
+(1 row)
+
+DROP TABLE xpath_test;
+CREATE TABLE xpath_test (id integer NOT NULL, t text);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+ id 
+----
+(0 rows)
+
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+ id | doc 
+----+-----
+  1 |   1
+(1 row)
+
+create table articles (article_id integer, article_xml xml, date_entered date);
+insert into articles (article_id, article_xml, date_entered)
+values (2, '<article><author>test</author><pages>37</pages></article>', now());
+SELECT * FROM
+xpath_table('article_id',
+            'article_xml',
+            'articles',
+            '/article/author|/article/pages|/article/title',
+            'date_entered > ''2003-01-01'' ')
+AS t(article_id integer, author text, page_count integer, title text);
+ article_id | author | page_count | title 
+------------+--------+------------+-------
+          2 | test   |         37 | 
+(1 row)
+
+-- this used to fail when invoked a second time
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+ERROR:  xslt_process() is not available without libxslt
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+ERROR:  xslt_process() is not available without libxslt
+create table t1 (id integer, xml_data xml);
+insert into t1 (id, xml_data)
+values
+(1, '<attributes><attribute name="attr_1">Some
+Value</attribute></attributes>');
+create index idx_xpath on t1 ( xpath_string
+('/attributes/attribute[@name="attr_1"]/text()', xml_data::text));
+SELECT xslt_process('<employee><name>cim</name><age>30</age><pay>400</pay></employee>'::text, $$<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
+  <xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
+  <xsl:strip-space elements="*"/>
+  <xsl:param name="n1"/>
+  <xsl:param name="n2"/>
+  <xsl:param name="n3"/>
+  <xsl:param name="n4"/>
+  <xsl:param name="n5" select="'me'"/>
+  <xsl:template match="*">
+    <xsl:element name="samples">
+      <xsl:element name="sample">
+        <xsl:value-of select="$n1"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n2"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n3"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n4"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n5"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n6"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n7"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n8"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n9"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n10"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n11"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n12"/>
+      </xsl:element>
+    </xsl:element>
+  </xsl:template>
+</xsl:stylesheet>$$::text, 'n1="v1",n2="v2",n3="v3",n4="v4",n5="v5",n6="v6",n7="v7",n8="v8",n9="v9",n10="v10",n11="v11",n12="v12"'::text);
+ERROR:  xslt_process() is not available without libxslt
+-- possible security exploit
+SELECT xslt_process('<xml><foo>Hello from XML</foo></xml>',
+$$<xsl:stylesheet version="1.0"
+      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+      xmlns:sax="http://icl.com/saxon"
+      extension-element-prefixes="sax">
+
+  <xsl:template match="//foo">
+    <sax:output href="0wn3d.txt" method="text">
+      <xsl:value-of select="'0wn3d via xml2 extension and libxslt'"/>
+      <xsl:apply-templates/>
+    </sax:output>
+  </xsl:template>
+</xsl:stylesheet>$$);
+ERROR:  xslt_process() is not available without libxslt
diff --git a/contrib/xml2/meson.build b/contrib/xml2/meson.build
new file mode 100644
index 0000000..4989567
--- /dev/null
+++ b/contrib/xml2/meson.build
@@ -0,0 +1,43 @@
+# Copyright (c) 2022-2023, PostgreSQL Global Development Group
+
+if not libxml.found()
+  subdir_done()
+endif
+
+xml2_sources = files(
+  'xpath.c',
+  'xslt_proc.c',
+)
+
+if host_system == 'windows'
+  xml2_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+    '--NAME', 'pgxml',
+    '--FILEDESC', 'xml2 - XPath querying and XSLT',])
+endif
+
+xml2 = shared_module('pgxml',
+  xml2_sources,
+  c_pch: pch_postgres_h,
+  kwargs: contrib_mod_args + {
+    'dependencies': [libxml, libxslt, contrib_mod_args['dependencies']],
+  },
+)
+contrib_targets += xml2
+
+install_data(
+  'xml2--1.0--1.1.sql',
+  'xml2--1.1.sql',
+  'xml2.control',
+  kwargs: contrib_data_args,
+)
+
+tests += {
+  'name': 'xml2',
+  'sd': meson.current_source_dir(),
+  'bd': meson.current_build_dir(),
+  'regress': {
+    'sql': [
+      'xml2',
+    ],
+  },
+}
diff --git a/contrib/xml2/sql/xml2.sql b/contrib/xml2/sql/xml2.sql
new file mode 100644
index 0000000..ac49cfa
--- /dev/null
+++ b/contrib/xml2/sql/xml2.sql
@@ -0,0 +1,139 @@
+CREATE EXTENSION xml2;
+
+select query_to_xml('select 1 as x',true,false,'');
+
+select xslt_process( query_to_xml('select x from generate_series(1,5) as
+x',true,false,'')::text,
+$$<xsl:stylesheet version="1.0"
+               xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:output method="xml" indent="yes" />
+<xsl:template match="*">
+  <xsl:copy>
+     <xsl:copy-of select="@*" />
+     <xsl:apply-templates />
+  </xsl:copy>
+</xsl:template>
+<xsl:template match="comment()|processing-instruction()">
+  <xsl:copy />
+</xsl:template>
+</xsl:stylesheet>
+$$::text);
+
+CREATE TABLE xpath_test (id integer NOT NULL, t xml);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+
+DROP TABLE xpath_test;
+CREATE TABLE xpath_test (id integer NOT NULL, t text);
+INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4);
+SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
+as t(id int4, doc int4);
+
+create table articles (article_id integer, article_xml xml, date_entered date);
+insert into articles (article_id, article_xml, date_entered)
+values (2, '<article><author>test</author><pages>37</pages></article>', now());
+SELECT * FROM
+xpath_table('article_id',
+            'article_xml',
+            'articles',
+            '/article/author|/article/pages|/article/title',
+            'date_entered > ''2003-01-01'' ')
+AS t(article_id integer, author text, page_count integer, title text);
+
+-- this used to fail when invoked a second time
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+
+select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
+xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:template match="@*|node()">
+      <xsl:copy>
+         <xsl:apply-templates select="@*|node()"/>
+      </xsl:copy>
+   </xsl:template>
+</xsl:stylesheet>$$)::xml;
+
+create table t1 (id integer, xml_data xml);
+insert into t1 (id, xml_data)
+values
+(1, '<attributes><attribute name="attr_1">Some
+Value</attribute></attributes>');
+
+create index idx_xpath on t1 ( xpath_string
+('/attributes/attribute[@name="attr_1"]/text()', xml_data::text));
+
+SELECT xslt_process('<employee><name>cim</name><age>30</age><pay>400</pay></employee>'::text, $$<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
+  <xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
+  <xsl:strip-space elements="*"/>
+  <xsl:param name="n1"/>
+  <xsl:param name="n2"/>
+  <xsl:param name="n3"/>
+  <xsl:param name="n4"/>
+  <xsl:param name="n5" select="'me'"/>
+  <xsl:template match="*">
+    <xsl:element name="samples">
+      <xsl:element name="sample">
+        <xsl:value-of select="$n1"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n2"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n3"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n4"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n5"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n6"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n7"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n8"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n9"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n10"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n11"/>
+      </xsl:element>
+      <xsl:element name="sample">
+        <xsl:value-of select="$n12"/>
+      </xsl:element>
+    </xsl:element>
+  </xsl:template>
+</xsl:stylesheet>$$::text, 'n1="v1",n2="v2",n3="v3",n4="v4",n5="v5",n6="v6",n7="v7",n8="v8",n9="v9",n10="v10",n11="v11",n12="v12"'::text);
+
+-- possible security exploit
+SELECT xslt_process('<xml><foo>Hello from XML</foo></xml>',
+$$<xsl:stylesheet version="1.0"
+      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+      xmlns:sax="http://icl.com/saxon"
+      extension-element-prefixes="sax">
+
+  <xsl:template match="//foo">
+    <sax:output href="0wn3d.txt" method="text">
+      <xsl:value-of select="'0wn3d via xml2 extension and libxslt'"/>
+      <xsl:apply-templates/>
+    </sax:output>
+  </xsl:template>
+</xsl:stylesheet>$$);
diff --git a/contrib/xml2/xml2--1.0--1.1.sql b/contrib/xml2/xml2--1.0--1.1.sql
new file mode 100644
index 0000000..350afb0
--- /dev/null
+++ b/contrib/xml2/xml2--1.0--1.1.sql
@@ -0,0 +1,18 @@
+/* contrib/xml2/xml2--1.0--1.1.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION xml2 UPDATE TO '1.1'" to load this file. \quit
+
+ALTER FUNCTION xml_valid(text) PARALLEL SAFE;
+ALTER FUNCTION xml_encode_special_chars(text) PARALLEL SAFE;
+ALTER FUNCTION xpath_string(text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_nodeset(text, text, text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_number(text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_bool(text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_list(text, text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_list(text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_nodeset(text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_nodeset(text, text, text) PARALLEL SAFE;
+ALTER FUNCTION xpath_table(text, text, text, text, text) PARALLEL SAFE;
+ALTER FUNCTION xslt_process(text, text, text) PARALLEL SAFE;
+ALTER FUNCTION xslt_process(text, text) PARALLEL SAFE;
diff --git a/contrib/xml2/xml2--1.1.sql b/contrib/xml2/xml2--1.1.sql
new file mode 100644
index 0000000..671372c
--- /dev/null
+++ b/contrib/xml2/xml2--1.1.sql
@@ -0,0 +1,73 @@
+/* contrib/xml2/xml2--1.1.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION xml2" to load this file. \quit
+
+--SQL for XML parser
+
+-- deprecated old name for xml_is_well_formed
+CREATE FUNCTION xml_valid(text) RETURNS bool
+AS 'xml_is_well_formed'
+LANGUAGE INTERNAL STRICT STABLE PARALLEL SAFE;
+
+CREATE FUNCTION xml_encode_special_chars(text) RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_string(text,text) RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_nodeset(text,text,text,text) RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_number(text,text) RETURNS float4
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_bool(text,text) RETURNS boolean
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+-- List function
+
+CREATE FUNCTION xpath_list(text,text,text) RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_list(text,text) RETURNS text
+AS 'SELECT xpath_list($1,$2,'','')'
+LANGUAGE SQL STRICT IMMUTABLE PARALLEL SAFE;
+
+-- Wrapper functions for nodeset where no tags needed
+
+CREATE FUNCTION xpath_nodeset(text,text)
+RETURNS text
+AS 'SELECT xpath_nodeset($1,$2,'''','''')'
+LANGUAGE SQL STRICT IMMUTABLE PARALLEL SAFE;
+
+CREATE FUNCTION xpath_nodeset(text,text,text)
+RETURNS text
+AS 'SELECT xpath_nodeset($1,$2,'''',$3)'
+LANGUAGE SQL STRICT IMMUTABLE PARALLEL SAFE;
+
+-- Table function
+
+CREATE FUNCTION xpath_table(text,text,text,text,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT STABLE PARALLEL SAFE;
+
+-- XSLT functions
+
+CREATE FUNCTION xslt_process(text,text,text)
+RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+-- the function checks for the correct argument count
+CREATE FUNCTION xslt_process(text,text)
+RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE PARALLEL SAFE;
diff --git a/contrib/xml2/xml2.control b/contrib/xml2/xml2.control
new file mode 100644
index 0000000..ba2c059
--- /dev/null
+++ b/contrib/xml2/xml2.control
@@ -0,0 +1,6 @@
+# xml2 extension
+comment = 'XPath querying and XSLT'
+default_version = '1.1'
+module_pathname = '$libdir/pgxml'
+# XXX do we still need this to be non-relocatable?
+relocatable = false
diff --git a/contrib/xml2/xpath.c b/contrib/xml2/xpath.c
new file mode 100644
index 0000000..9464193
--- /dev/null
+++ b/contrib/xml2/xpath.c
@@ -0,0 +1,745 @@
+/*
+ * contrib/xml2/xpath.c
+ *
+ * Parser interface for DOM-based parser (libxml) rather than
+ * stream-based SAX-type parser
+ */
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "executor/spi.h"
+#include "fmgr.h"
+#include "funcapi.h"
+#include "lib/stringinfo.h"
+#include "miscadmin.h"
+#include "utils/builtins.h"
+#include "utils/xml.h"
+
+/* libxml includes */
+
+#include <libxml/xpath.h>
+#include <libxml/tree.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/xmlerror.h>
+#include <libxml/parserInternals.h>
+
+PG_MODULE_MAGIC;
+
+/* exported for use by xslt_proc.c */
+
+PgXmlErrorContext *pgxml_parser_init(PgXmlStrictness strictness);
+
+/* workspace for pgxml_xpath() */
+
+typedef struct
+{
+	xmlDocPtr	doctree;
+	xmlXPathContextPtr ctxt;
+	xmlXPathObjectPtr res;
+} xpath_workspace;
+
+/* local declarations */
+
+static xmlChar *pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
+								   xmlChar *toptagname, xmlChar *septagname,
+								   xmlChar *plainsep);
+
+static text *pgxml_result_to_text(xmlXPathObjectPtr res, xmlChar *toptag,
+								  xmlChar *septag, xmlChar *plainsep);
+
+static xmlChar *pgxml_texttoxmlchar(text *textstring);
+
+static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar *xpath,
+									 xpath_workspace *workspace);
+
+static void cleanup_workspace(xpath_workspace *workspace);
+
+
+/*
+ * Initialize for xml parsing.
+ *
+ * As with the underlying pg_xml_init function, calls to this MUST be followed
+ * by a PG_TRY block that guarantees that pg_xml_done is called.
+ */
+PgXmlErrorContext *
+pgxml_parser_init(PgXmlStrictness strictness)
+{
+	PgXmlErrorContext *xmlerrcxt;
+
+	/* Set up error handling (we share the core's error handler) */
+	xmlerrcxt = pg_xml_init(strictness);
+
+	/* Note: we're assuming an elog cannot be thrown by the following calls */
+
+	/* Initialize libxml */
+	xmlInitParser();
+
+	xmlSubstituteEntitiesDefault(1);
+
+	return xmlerrcxt;
+}
+
+
+/* Encodes special characters (<, >, &, " and \r) as XML entities */
+
+PG_FUNCTION_INFO_V1(xml_encode_special_chars);
+
+Datum
+xml_encode_special_chars(PG_FUNCTION_ARGS)
+{
+	text	   *tin = PG_GETARG_TEXT_PP(0);
+	text	   *tout;
+	xmlChar    *ts,
+			   *tt;
+
+	ts = pgxml_texttoxmlchar(tin);
+
+	tt = xmlEncodeSpecialChars(NULL, ts);
+
+	pfree(ts);
+
+	tout = cstring_to_text((char *) tt);
+
+	xmlFree(tt);
+
+	PG_RETURN_TEXT_P(tout);
+}
+
+/*
+ * Function translates a nodeset into a text representation
+ *
+ * iterates over each node in the set and calls xmlNodeDump to write it to
+ * an xmlBuffer -from which an xmlChar * string is returned.
+ *
+ * each representation is surrounded by <tagname> ... </tagname>
+ *
+ * plainsep is an ordinary (not tag) separator - if used, then nodes are
+ * cast to string as output method
+ */
+static xmlChar *
+pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
+				   xmlChar *toptagname,
+				   xmlChar *septagname,
+				   xmlChar *plainsep)
+{
+	xmlBufferPtr buf;
+	xmlChar    *result;
+	int			i;
+
+	buf = xmlBufferCreate();
+
+	if ((toptagname != NULL) && (xmlStrlen(toptagname) > 0))
+	{
+		xmlBufferWriteChar(buf, "<");
+		xmlBufferWriteCHAR(buf, toptagname);
+		xmlBufferWriteChar(buf, ">");
+	}
+	if (nodeset != NULL)
+	{
+		for (i = 0; i < nodeset->nodeNr; i++)
+		{
+			if (plainsep != NULL)
+			{
+				xmlBufferWriteCHAR(buf,
+								   xmlXPathCastNodeToString(nodeset->nodeTab[i]));
+
+				/* If this isn't the last entry, write the plain sep. */
+				if (i < (nodeset->nodeNr) - 1)
+					xmlBufferWriteChar(buf, (char *) plainsep);
+			}
+			else
+			{
+				if ((septagname != NULL) && (xmlStrlen(septagname) > 0))
+				{
+					xmlBufferWriteChar(buf, "<");
+					xmlBufferWriteCHAR(buf, septagname);
+					xmlBufferWriteChar(buf, ">");
+				}
+				xmlNodeDump(buf,
+							nodeset->nodeTab[i]->doc,
+							nodeset->nodeTab[i],
+							1, 0);
+
+				if ((septagname != NULL) && (xmlStrlen(septagname) > 0))
+				{
+					xmlBufferWriteChar(buf, "</");
+					xmlBufferWriteCHAR(buf, septagname);
+					xmlBufferWriteChar(buf, ">");
+				}
+			}
+		}
+	}
+
+	if ((toptagname != NULL) && (xmlStrlen(toptagname) > 0))
+	{
+		xmlBufferWriteChar(buf, "</");
+		xmlBufferWriteCHAR(buf, toptagname);
+		xmlBufferWriteChar(buf, ">");
+	}
+	result = xmlStrdup(buf->content);
+	xmlBufferFree(buf);
+	return result;
+}
+
+
+/* Translate a PostgreSQL "varlena" -i.e. a variable length parameter
+ * into the libxml2 representation
+ */
+static xmlChar *
+pgxml_texttoxmlchar(text *textstring)
+{
+	return (xmlChar *) text_to_cstring(textstring);
+}
+
+/* Publicly visible XPath functions */
+
+/*
+ * This is a "raw" xpath function. Check that it returns child elements
+ * properly
+ */
+PG_FUNCTION_INFO_V1(xpath_nodeset);
+
+Datum
+xpath_nodeset(PG_FUNCTION_ARGS)
+{
+	text	   *document = PG_GETARG_TEXT_PP(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_PP(1);	/* XPath expression */
+	xmlChar    *toptag = pgxml_texttoxmlchar(PG_GETARG_TEXT_PP(2));
+	xmlChar    *septag = pgxml_texttoxmlchar(PG_GETARG_TEXT_PP(3));
+	xmlChar    *xpath;
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
+
+	xpath = pgxml_texttoxmlchar(xpathsupp);
+
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	xpres = pgxml_result_to_text(res, toptag, septag, NULL);
+
+	cleanup_workspace(&workspace);
+
+	pfree(xpath);
+
+	if (xpres == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_TEXT_P(xpres);
+}
+
+/*
+ * The following function is almost identical, but returns the elements in
+ * a list.
+ */
+PG_FUNCTION_INFO_V1(xpath_list);
+
+Datum
+xpath_list(PG_FUNCTION_ARGS)
+{
+	text	   *document = PG_GETARG_TEXT_PP(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_PP(1);	/* XPath expression */
+	xmlChar    *plainsep = pgxml_texttoxmlchar(PG_GETARG_TEXT_PP(2));
+	xmlChar    *xpath;
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
+
+	xpath = pgxml_texttoxmlchar(xpathsupp);
+
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	xpres = pgxml_result_to_text(res, NULL, NULL, plainsep);
+
+	cleanup_workspace(&workspace);
+
+	pfree(xpath);
+
+	if (xpres == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_TEXT_P(xpres);
+}
+
+
+PG_FUNCTION_INFO_V1(xpath_string);
+
+Datum
+xpath_string(PG_FUNCTION_ARGS)
+{
+	text	   *document = PG_GETARG_TEXT_PP(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_PP(1);	/* XPath expression */
+	xmlChar    *xpath;
+	int32		pathsize;
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
+
+	pathsize = VARSIZE_ANY_EXHDR(xpathsupp);
+
+	/*
+	 * We encapsulate the supplied path with "string()" = 8 chars + 1 for NUL
+	 * at end
+	 */
+	/* We could try casting to string using the libxml function? */
+
+	xpath = (xmlChar *) palloc(pathsize + 9);
+	memcpy((char *) xpath, "string(", 7);
+	memcpy((char *) (xpath + 7), VARDATA_ANY(xpathsupp), pathsize);
+	xpath[pathsize + 7] = ')';
+	xpath[pathsize + 8] = '\0';
+
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	xpres = pgxml_result_to_text(res, NULL, NULL, NULL);
+
+	cleanup_workspace(&workspace);
+
+	pfree(xpath);
+
+	if (xpres == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_TEXT_P(xpres);
+}
+
+
+PG_FUNCTION_INFO_V1(xpath_number);
+
+Datum
+xpath_number(PG_FUNCTION_ARGS)
+{
+	text	   *document = PG_GETARG_TEXT_PP(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_PP(1);	/* XPath expression */
+	xmlChar    *xpath;
+	float4		fRes;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
+
+	xpath = pgxml_texttoxmlchar(xpathsupp);
+
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	pfree(xpath);
+
+	if (res == NULL)
+		PG_RETURN_NULL();
+
+	fRes = xmlXPathCastToNumber(res);
+
+	cleanup_workspace(&workspace);
+
+	if (xmlXPathIsNaN(fRes))
+		PG_RETURN_NULL();
+
+	PG_RETURN_FLOAT4(fRes);
+}
+
+
+PG_FUNCTION_INFO_V1(xpath_bool);
+
+Datum
+xpath_bool(PG_FUNCTION_ARGS)
+{
+	text	   *document = PG_GETARG_TEXT_PP(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_PP(1);	/* XPath expression */
+	xmlChar    *xpath;
+	int			bRes;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
+
+	xpath = pgxml_texttoxmlchar(xpathsupp);
+
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	pfree(xpath);
+
+	if (res == NULL)
+		PG_RETURN_BOOL(false);
+
+	bRes = xmlXPathCastToBoolean(res);
+
+	cleanup_workspace(&workspace);
+
+	PG_RETURN_BOOL(bRes);
+}
+
+
+
+/* Core function to evaluate XPath query */
+
+static xmlXPathObjectPtr
+pgxml_xpath(text *document, xmlChar *xpath, xpath_workspace *workspace)
+{
+	int32		docsize = VARSIZE_ANY_EXHDR(document);
+	PgXmlErrorContext *xmlerrcxt;
+	xmlXPathCompExprPtr comppath;
+
+	workspace->doctree = NULL;
+	workspace->ctxt = NULL;
+	workspace->res = NULL;
+
+	xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
+
+	PG_TRY();
+	{
+		workspace->doctree = xmlParseMemory((char *) VARDATA_ANY(document),
+											docsize);
+		if (workspace->doctree != NULL)
+		{
+			workspace->ctxt = xmlXPathNewContext(workspace->doctree);
+			workspace->ctxt->node = xmlDocGetRootElement(workspace->doctree);
+
+			/* compile the path */
+			comppath = xmlXPathCompile(xpath);
+			if (comppath == NULL)
+				xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+							"XPath Syntax Error");
+
+			/* Now evaluate the path expression. */
+			workspace->res = xmlXPathCompiledEval(comppath, workspace->ctxt);
+
+			xmlXPathFreeCompExpr(comppath);
+		}
+	}
+	PG_CATCH();
+	{
+		cleanup_workspace(workspace);
+
+		pg_xml_done(xmlerrcxt, true);
+
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	if (workspace->res == NULL)
+		cleanup_workspace(workspace);
+
+	pg_xml_done(xmlerrcxt, false);
+
+	return workspace->res;
+}
+
+/* Clean up after processing the result of pgxml_xpath() */
+static void
+cleanup_workspace(xpath_workspace *workspace)
+{
+	if (workspace->res)
+		xmlXPathFreeObject(workspace->res);
+	workspace->res = NULL;
+	if (workspace->ctxt)
+		xmlXPathFreeContext(workspace->ctxt);
+	workspace->ctxt = NULL;
+	if (workspace->doctree)
+		xmlFreeDoc(workspace->doctree);
+	workspace->doctree = NULL;
+}
+
+static text *
+pgxml_result_to_text(xmlXPathObjectPtr res,
+					 xmlChar *toptag,
+					 xmlChar *septag,
+					 xmlChar *plainsep)
+{
+	xmlChar    *xpresstr;
+	text	   *xpres;
+
+	if (res == NULL)
+		return NULL;
+
+	switch (res->type)
+	{
+		case XPATH_NODESET:
+			xpresstr = pgxmlNodeSetToText(res->nodesetval,
+										  toptag,
+										  septag, plainsep);
+			break;
+
+		case XPATH_STRING:
+			xpresstr = xmlStrdup(res->stringval);
+			break;
+
+		default:
+			elog(NOTICE, "unsupported XQuery result: %d", res->type);
+			xpresstr = xmlStrdup((const xmlChar *) "<unsupported/>");
+	}
+
+	/* Now convert this result back to text */
+	xpres = cstring_to_text((char *) xpresstr);
+
+	/* Free various storage */
+	xmlFree(xpresstr);
+
+	return xpres;
+}
+
+/*
+ * xpath_table is a table function. It needs some tidying (as do the
+ * other functions here!
+ */
+PG_FUNCTION_INFO_V1(xpath_table);
+
+Datum
+xpath_table(PG_FUNCTION_ARGS)
+{
+	/* Function parameters */
+	char	   *pkeyfield = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	char	   *xmlfield = text_to_cstring(PG_GETARG_TEXT_PP(1));
+	char	   *relname = text_to_cstring(PG_GETARG_TEXT_PP(2));
+	char	   *xpathset = text_to_cstring(PG_GETARG_TEXT_PP(3));
+	char	   *condition = text_to_cstring(PG_GETARG_TEXT_PP(4));
+
+	/* SPI (input tuple) support */
+	SPITupleTable *tuptable;
+	HeapTuple	spi_tuple;
+	TupleDesc	spi_tupdesc;
+
+
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	AttInMetadata *attinmeta;
+
+	char	  **values;
+	xmlChar   **xpaths;
+	char	   *pos;
+	const char *pathsep = "|";
+
+	int			numpaths;
+	int			ret;
+	uint64		proc;
+	int			j;
+	int			rownr;			/* For issuing multiple rows from one original
+								 * document */
+	bool		had_values;		/* To determine end of nodeset results */
+	StringInfoData query_buf;
+	PgXmlErrorContext *xmlerrcxt;
+	volatile xmlDocPtr doctree = NULL;
+
+	InitMaterializedSRF(fcinfo, MAT_SRF_USE_EXPECTED_DESC);
+
+	/* must have at least one output column (for the pkey) */
+	if (rsinfo->setDesc->natts < 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("xpath_table must have at least one output column")));
+
+	/*
+	 * At the moment we assume that the returned attributes make sense for the
+	 * XPath specified (i.e. we trust the caller). It's not fatal if they get
+	 * it wrong - the input function for the column type will raise an error
+	 * if the path result can't be converted into the correct binary
+	 * representation.
+	 */
+
+	attinmeta = TupleDescGetAttInMetadata(rsinfo->setDesc);
+
+	values = (char **) palloc(rsinfo->setDesc->natts * sizeof(char *));
+	xpaths = (xmlChar **) palloc(rsinfo->setDesc->natts * sizeof(xmlChar *));
+
+	/*
+	 * Split XPaths. xpathset is a writable CString.
+	 *
+	 * Note that we stop splitting once we've done all needed for tupdesc
+	 */
+	numpaths = 0;
+	pos = xpathset;
+	while (numpaths < (rsinfo->setDesc->natts - 1))
+	{
+		xpaths[numpaths++] = (xmlChar *) pos;
+		pos = strstr(pos, pathsep);
+		if (pos != NULL)
+		{
+			*pos = '\0';
+			pos++;
+		}
+		else
+			break;
+	}
+
+	/* Now build query */
+	initStringInfo(&query_buf);
+
+	/* Build initial sql statement */
+	appendStringInfo(&query_buf, "SELECT %s, %s FROM %s WHERE %s",
+					 pkeyfield,
+					 xmlfield,
+					 relname,
+					 condition);
+
+	if ((ret = SPI_connect()) < 0)
+		elog(ERROR, "xpath_table: SPI_connect returned %d", ret);
+
+	if ((ret = SPI_exec(query_buf.data, 0)) != SPI_OK_SELECT)
+		elog(ERROR, "xpath_table: SPI execution failed for query %s",
+			 query_buf.data);
+
+	proc = SPI_processed;
+	tuptable = SPI_tuptable;
+	spi_tupdesc = tuptable->tupdesc;
+
+	/*
+	 * Check that SPI returned correct result. If you put a comma into one of
+	 * the function parameters, this will catch it when the SPI query returns
+	 * e.g. 3 columns.
+	 */
+	if (spi_tupdesc->natts != 2)
+	{
+		ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						errmsg("expression returning multiple columns is not valid in parameter list"),
+						errdetail("Expected two columns in SPI result, got %d.", spi_tupdesc->natts)));
+	}
+
+	/*
+	 * Setup the parser.  This should happen after we are done evaluating the
+	 * query, in case it calls functions that set up libxml differently.
+	 */
+	xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
+
+	PG_TRY();
+	{
+		/* For each row i.e. document returned from SPI */
+		uint64		i;
+
+		for (i = 0; i < proc; i++)
+		{
+			char	   *pkey;
+			char	   *xmldoc;
+			xmlXPathContextPtr ctxt;
+			xmlXPathObjectPtr res;
+			xmlChar    *resstr;
+			xmlXPathCompExprPtr comppath;
+			HeapTuple	ret_tuple;
+
+			/* Extract the row data as C Strings */
+			spi_tuple = tuptable->vals[i];
+			pkey = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+			xmldoc = SPI_getvalue(spi_tuple, spi_tupdesc, 2);
+
+			/*
+			 * Clear the values array, so that not-well-formed documents
+			 * return NULL in all columns.  Note that this also means that
+			 * spare columns will be NULL.
+			 */
+			for (j = 0; j < rsinfo->setDesc->natts; j++)
+				values[j] = NULL;
+
+			/* Insert primary key */
+			values[0] = pkey;
+
+			/* Parse the document */
+			if (xmldoc)
+				doctree = xmlParseMemory(xmldoc, strlen(xmldoc));
+			else				/* treat NULL as not well-formed */
+				doctree = NULL;
+
+			if (doctree == NULL)
+			{
+				/* not well-formed, so output all-NULL tuple */
+				ret_tuple = BuildTupleFromCStrings(attinmeta, values);
+				tuplestore_puttuple(rsinfo->setResult, ret_tuple);
+				heap_freetuple(ret_tuple);
+			}
+			else
+			{
+				/* New loop here - we have to deal with nodeset results */
+				rownr = 0;
+
+				do
+				{
+					/* Now evaluate the set of xpaths. */
+					had_values = false;
+					for (j = 0; j < numpaths; j++)
+					{
+						ctxt = xmlXPathNewContext(doctree);
+						ctxt->node = xmlDocGetRootElement(doctree);
+
+						/* compile the path */
+						comppath = xmlXPathCompile(xpaths[j]);
+						if (comppath == NULL)
+							xml_ereport(xmlerrcxt, ERROR,
+										ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+										"XPath Syntax Error");
+
+						/* Now evaluate the path expression. */
+						res = xmlXPathCompiledEval(comppath, ctxt);
+						xmlXPathFreeCompExpr(comppath);
+
+						if (res != NULL)
+						{
+							switch (res->type)
+							{
+								case XPATH_NODESET:
+									/* We see if this nodeset has enough nodes */
+									if (res->nodesetval != NULL &&
+										rownr < res->nodesetval->nodeNr)
+									{
+										resstr = xmlXPathCastNodeToString(res->nodesetval->nodeTab[rownr]);
+										had_values = true;
+									}
+									else
+										resstr = NULL;
+
+									break;
+
+								case XPATH_STRING:
+									resstr = xmlStrdup(res->stringval);
+									break;
+
+								default:
+									elog(NOTICE, "unsupported XQuery result: %d", res->type);
+									resstr = xmlStrdup((const xmlChar *) "<unsupported/>");
+							}
+
+							/*
+							 * Insert this into the appropriate column in the
+							 * result tuple.
+							 */
+							values[j + 1] = (char *) resstr;
+						}
+						xmlXPathFreeContext(ctxt);
+					}
+
+					/* Now add the tuple to the output, if there is one. */
+					if (had_values)
+					{
+						ret_tuple = BuildTupleFromCStrings(attinmeta, values);
+						tuplestore_puttuple(rsinfo->setResult, ret_tuple);
+						heap_freetuple(ret_tuple);
+					}
+
+					rownr++;
+				} while (had_values);
+			}
+
+			if (doctree != NULL)
+				xmlFreeDoc(doctree);
+			doctree = NULL;
+
+			if (pkey)
+				pfree(pkey);
+			if (xmldoc)
+				pfree(xmldoc);
+		}
+	}
+	PG_CATCH();
+	{
+		if (doctree != NULL)
+			xmlFreeDoc(doctree);
+
+		pg_xml_done(xmlerrcxt, true);
+
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	if (doctree != NULL)
+		xmlFreeDoc(doctree);
+
+	pg_xml_done(xmlerrcxt, false);
+
+	SPI_finish();
+
+	/*
+	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
+	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
+	 * rsinfo->setDesc is set to the tuple description that we actually used
+	 * to build our tuples with, so the caller can verify we did what it was
+	 * expecting.
+	 */
+	return (Datum) 0;
+}
diff --git a/contrib/xml2/xslt_proc.c b/contrib/xml2/xslt_proc.c
new file mode 100644
index 0000000..2189bca
--- /dev/null
+++ b/contrib/xml2/xslt_proc.c
@@ -0,0 +1,256 @@
+/*
+ * contrib/xml2/xslt_proc.c
+ *
+ * XSLT processing functions (requiring libxslt)
+ *
+ * John Gray, for Torchbox 2003-04-01
+ */
+#include "postgres.h"
+
+#include "executor/spi.h"
+#include "fmgr.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "utils/builtins.h"
+#include "utils/xml.h"
+
+#ifdef USE_LIBXSLT
+
+/* libxml includes */
+
+#include <libxml/xpath.h>
+#include <libxml/tree.h>
+#include <libxml/xmlmemory.h>
+
+/* libxslt includes */
+
+#include <libxslt/xslt.h>
+#include <libxslt/xsltInternals.h>
+#include <libxslt/security.h>
+#include <libxslt/transform.h>
+#include <libxslt/xsltutils.h>
+#endif							/* USE_LIBXSLT */
+
+
+#ifdef USE_LIBXSLT
+
+/* declarations to come from xpath.c */
+extern PgXmlErrorContext *pgxml_parser_init(PgXmlStrictness strictness);
+
+/* local defs */
+static const char **parse_params(text *paramstr);
+#endif							/* USE_LIBXSLT */
+
+
+PG_FUNCTION_INFO_V1(xslt_process);
+
+Datum
+xslt_process(PG_FUNCTION_ARGS)
+{
+#ifdef USE_LIBXSLT
+
+	text	   *doct = PG_GETARG_TEXT_PP(0);
+	text	   *ssheet = PG_GETARG_TEXT_PP(1);
+	text	   *result;
+	text	   *paramstr;
+	const char **params;
+	PgXmlErrorContext *xmlerrcxt;
+	volatile xsltStylesheetPtr stylesheet = NULL;
+	volatile xmlDocPtr doctree = NULL;
+	volatile xmlDocPtr restree = NULL;
+	volatile xsltSecurityPrefsPtr xslt_sec_prefs = NULL;
+	volatile xsltTransformContextPtr xslt_ctxt = NULL;
+	volatile int resstat = -1;
+	xmlChar    *resstr = NULL;
+	int			reslen = 0;
+
+	if (fcinfo->nargs == 3)
+	{
+		paramstr = PG_GETARG_TEXT_PP(2);
+		params = parse_params(paramstr);
+	}
+	else
+	{
+		/* No parameters */
+		params = (const char **) palloc(sizeof(char *));
+		params[0] = NULL;
+	}
+
+	/* Setup parser */
+	xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
+
+	PG_TRY();
+	{
+		xmlDocPtr	ssdoc;
+		bool		xslt_sec_prefs_error;
+
+		/* Parse document */
+		doctree = xmlParseMemory((char *) VARDATA_ANY(doct),
+								 VARSIZE_ANY_EXHDR(doct));
+
+		if (doctree == NULL)
+			xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+						"error parsing XML document");
+
+		/* Same for stylesheet */
+		ssdoc = xmlParseMemory((char *) VARDATA_ANY(ssheet),
+							   VARSIZE_ANY_EXHDR(ssheet));
+
+		if (ssdoc == NULL)
+			xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+						"error parsing stylesheet as XML document");
+
+		/* After this call we need not free ssdoc separately */
+		stylesheet = xsltParseStylesheetDoc(ssdoc);
+
+		if (stylesheet == NULL)
+			xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+						"failed to parse stylesheet");
+
+		xslt_ctxt = xsltNewTransformContext(stylesheet, doctree);
+
+		xslt_sec_prefs_error = false;
+		if ((xslt_sec_prefs = xsltNewSecurityPrefs()) == NULL)
+			xslt_sec_prefs_error = true;
+
+		if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_READ_FILE,
+								 xsltSecurityForbid) != 0)
+			xslt_sec_prefs_error = true;
+		if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_WRITE_FILE,
+								 xsltSecurityForbid) != 0)
+			xslt_sec_prefs_error = true;
+		if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_CREATE_DIRECTORY,
+								 xsltSecurityForbid) != 0)
+			xslt_sec_prefs_error = true;
+		if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_READ_NETWORK,
+								 xsltSecurityForbid) != 0)
+			xslt_sec_prefs_error = true;
+		if (xsltSetSecurityPrefs(xslt_sec_prefs, XSLT_SECPREF_WRITE_NETWORK,
+								 xsltSecurityForbid) != 0)
+			xslt_sec_prefs_error = true;
+		if (xsltSetCtxtSecurityPrefs(xslt_sec_prefs, xslt_ctxt) != 0)
+			xslt_sec_prefs_error = true;
+
+		if (xslt_sec_prefs_error)
+			ereport(ERROR,
+					(errmsg("could not set libxslt security preferences")));
+
+		restree = xsltApplyStylesheetUser(stylesheet, doctree, params,
+										  NULL, NULL, xslt_ctxt);
+
+		if (restree == NULL)
+			xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
+						"failed to apply stylesheet");
+
+		resstat = xsltSaveResultToString(&resstr, &reslen, restree, stylesheet);
+	}
+	PG_CATCH();
+	{
+		if (restree != NULL)
+			xmlFreeDoc(restree);
+		if (xslt_ctxt != NULL)
+			xsltFreeTransformContext(xslt_ctxt);
+		if (xslt_sec_prefs != NULL)
+			xsltFreeSecurityPrefs(xslt_sec_prefs);
+		if (stylesheet != NULL)
+			xsltFreeStylesheet(stylesheet);
+		if (doctree != NULL)
+			xmlFreeDoc(doctree);
+		xsltCleanupGlobals();
+
+		pg_xml_done(xmlerrcxt, true);
+
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	xmlFreeDoc(restree);
+	xsltFreeTransformContext(xslt_ctxt);
+	xsltFreeSecurityPrefs(xslt_sec_prefs);
+	xsltFreeStylesheet(stylesheet);
+	xmlFreeDoc(doctree);
+	xsltCleanupGlobals();
+
+	pg_xml_done(xmlerrcxt, false);
+
+	/* XXX this is pretty dubious, really ought to throw error instead */
+	if (resstat < 0)
+		PG_RETURN_NULL();
+
+	result = cstring_to_text_with_len((char *) resstr, reslen);
+
+	if (resstr)
+		xmlFree(resstr);
+
+	PG_RETURN_TEXT_P(result);
+#else							/* !USE_LIBXSLT */
+
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("xslt_process() is not available without libxslt")));
+	PG_RETURN_NULL();
+#endif							/* USE_LIBXSLT */
+}
+
+#ifdef USE_LIBXSLT
+
+static const char **
+parse_params(text *paramstr)
+{
+	char	   *pos;
+	char	   *pstr;
+	char	   *nvsep = "=";
+	char	   *itsep = ",";
+	const char **params;
+	int			max_params;
+	int			nparams;
+
+	pstr = text_to_cstring(paramstr);
+
+	max_params = 20;			/* must be even! */
+	params = (const char **) palloc((max_params + 1) * sizeof(char *));
+	nparams = 0;
+
+	pos = pstr;
+
+	while (*pos != '\0')
+	{
+		if (nparams >= max_params)
+		{
+			max_params *= 2;
+			params = (const char **) repalloc(params,
+											  (max_params + 1) * sizeof(char *));
+		}
+		params[nparams++] = pos;
+		pos = strstr(pos, nvsep);
+		if (pos != NULL)
+		{
+			*pos = '\0';
+			pos++;
+		}
+		else
+		{
+			/* No equal sign, so ignore this "parameter" */
+			nparams--;
+			break;
+		}
+
+		/* since max_params is even, we still have nparams < max_params */
+		params[nparams++] = pos;
+		pos = strstr(pos, itsep);
+		if (pos != NULL)
+		{
+			*pos = '\0';
+			pos++;
+		}
+		else
+			break;
+	}
+
+	/* Add the terminator marker; we left room for it in the palloc's */
+	params[nparams] = NULL;
+
+	return params;
+}
+
+#endif							/* USE_LIBXSLT */