Fix XML namespace declarations

The XSL stylesheets used a mix of incorrect or outdated namespace
declarations for XHTML, probably based on ancient advice and examples.
Clean all this up.

Besides improving correctness (although probably no impact in
practice, other than possible validation failures), this removes a
bunch of useless namespace declarations in the HTML output.

Reported-by: Andres Freund <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/20220213201618.qz6p6noon3wagr3f%40alap3.anarazel.de

5 files changed, 6 insertions, 11 deletions

diff --git a/doc/src/sgml/stylesheet-hh.xsl b/doc/src/sgml/stylesheet-hh.xsl
index 1b1ab4bbe9..6f4b706dac 100644
--- a/doc/src/sgml/stylesheet-hh.xsl
+++ b/doc/src/sgml/stylesheet-hh.xsl
@@ -1,8 +1,6 @@
 <?xml version='1.0'?>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-                version='1.0'
-                xmlns="http://www.w3.org/TR/xhtml1/transitional"
-                exclude-result-prefixes="#default">
+                version='1.0'>
 
 <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/htmlhelp/htmlhelp.xsl"/>
 <xsl:include href="stylesheet-common.xsl" />
diff --git a/doc/src/sgml/stylesheet-html-common.xsl b/doc/src/sgml/stylesheet-html-common.xsl
index d9961089c6..96dd2cc038 100644
--- a/doc/src/sgml/stylesheet-html-common.xsl
+++ b/doc/src/sgml/stylesheet-html-common.xsl
@@ -4,7 +4,8 @@
 %common.entities;
 ]>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-                version="1.0">
+                version="1.0"
+                xmlns="http://www.w3.org/1999/xhtml">
 
 <!--
   This file contains XSLT stylesheet customizations that are common to
diff --git a/doc/src/sgml/stylesheet-html-nochunk.xsl b/doc/src/sgml/stylesheet-html-nochunk.xsl
index 78add26a9f..8167127b93 100644
--- a/doc/src/sgml/stylesheet-html-nochunk.xsl
+++ b/doc/src/sgml/stylesheet-html-nochunk.xsl
@@ -1,8 +1,6 @@
 <?xml version='1.0'?>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-                version='1.0'
-                xmlns="http://www.w3.org/TR/xhtml1/transitional"
-                exclude-result-prefixes="#default">
+                version='1.0'>
 
 <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"/>
 <xsl:include href="stylesheet-common.xsl" />
diff --git a/doc/src/sgml/stylesheet-text.xsl b/doc/src/sgml/stylesheet-text.xsl
index 476b871870..529cc9ec38 100644
--- a/doc/src/sgml/stylesheet-text.xsl
+++ b/doc/src/sgml/stylesheet-text.xsl
@@ -1,8 +1,7 @@
 <?xml version='1.0'?>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 version='1.0'
-                xmlns="http://www.w3.org/TR/xhtml1/transitional"
-                exclude-result-prefixes="#default">
+                xmlns="http://www.w3.org/1999/xhtml">
 
 <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"/>
 <xsl:import href="stylesheet-common.xsl" />
diff --git a/doc/src/sgml/stylesheet.xsl b/doc/src/sgml/stylesheet.xsl
index 0eac594f0c..b6141303ab 100644
--- a/doc/src/sgml/stylesheet.xsl
+++ b/doc/src/sgml/stylesheet.xsl
@@ -1,8 +1,7 @@
 <?xml version='1.0'?>
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 version='1.0'
-                xmlns="http://www.w3.org/TR/xhtml1/transitional"
-                exclude-result-prefixes="#default">
+                xmlns="http://www.w3.org/1999/xhtml">
 
 <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/xhtml/chunk.xsl"/>
 <xsl:include href="stylesheet-common.xsl" />