Use RelaxNG for validation instead of DTD for DocBook 5.2

configure.php

@@ -24,6 +24,10 @@
 
 echo "configure.php: $cvs_id\n";
 
+const RNG_SCHEMA_DIR = __DIR__ . DIRECTORY_SEPARATOR . 'docbook' . DIRECTORY_SEPARATOR . 'docbook-v5.2-os' . DIRECTORY_SEPARATOR . 'rng' . DIRECTORY_SEPARATOR;
+const RNG_SCHEMA_FILE = RNG_SCHEMA_DIR . 'docbook.rng';
+const RNG_SCHEMA_XINCLUDE_FILE = RNG_SCHEMA_DIR . 'docbookxi.rng';
+
 function usage() // {{{
 {
     global $acd;
@@ -800,7 +804,7 @@ function getFileModificationHistory(): array {
 echo "Validating {$ac["INPUT_FILENAME"]}... ";
 flush();
 if ($ac['PARTIAL'] != '' && $ac['PARTIAL'] != 'no') { // {{{
-    $dom->validate(); // we don't care if the validation works or not
+    $dom->relaxNGValidate(RNG_SCHEMA_FILE); // we don't care if the validation works or not
     $node = $dom->getElementById($ac['PARTIAL']);
     if (!$node) {
         echo "failed.\n";
@@ -838,7 +842,11 @@ function getFileModificationHistory(): array {
 } // }}}
 
 $mxml = $ac["OUTPUT_FILENAME"];
-if ($dom->validate()) {
+
+/* TODO: For some reason libxml does not validate the RelaxNG schema unless reloading the document in full */
+$dom->save($mxml);
+$dom->load($mxml, $LIBXML_OPTS);
+if ($dom->relaxNGValidate(RNG_SCHEMA_FILE)) {
     echo "done.\n";
     printf("\nAll good. Saving %s... ", basename($ac["OUTPUT_FILENAME"]));
     flush();
@@ -870,26 +878,23 @@ function getFileModificationHistory(): array {
     exit(0); // Tell the shell that this script finished successfully.
 } else {
     echo "failed.\n";
-    echo "\nThe document didn't validate, ";
-
-    // Allow the .manual.xml file to be created, even if it is not valid.
-    if ($ac['FORCE_DOM_SAVE'] == 'yes') {
-        printf("writing %s anyway, and ", basename($ac["OUTPUT_FILENAME"]));
-        $dom->save($mxml);
-    }
-
-    if ($ac['DETAILED_ERRORMSG'] == 'yes') {
-        echo "trying to figure out what went wrong...\n";
-        echo "(This could take awhile. If you experience segfaults here, try again with --disable-xml-details)\n";
-        libxml_clear_errors(); // Clear the errors, they contain incorrect filename&line
-
-        $dom->load("{$ac['srcdir']}/{$ac["INPUT_FILENAME"]}", $LIBXML_OPTS | LIBXML_DTDVALID);
-        print_xml_errors();
+    echo "\nThe document didn't validate\n";
+
+    /**
+     * TODO: Integrate jing to explain schema violations as libxml is *useless*
+     * And this is not going to change for a while as the maintainer of libxml2 even acknowledges:
+     * > As it stands, libxml2's Relax NG validator doesn't seem suitable for production.
+     * cf. https://gitlab.gnome.org/GNOME/libxml2/-/issues/448
+     */
+    $output = shell_exec('java -jar ' . $srcdir . '/docbook/jing.jar ' . RNG_SCHEMA_FILE. ' ' . $acd['OUTPUT_FILENAME']);
+    if ($output === null) {
+        echo "Command failed do you have Java installed?";
     } else {
-        echo "here are the errors I got:\n";
-        echo "(If this isn't enough information, try again with --enable-xml-details)\n";
-        print_xml_errors(false);
+        echo $output;
     }
+    //echo 'Please use Jing and the:' . PHP_EOL
+    //    . 'java -jar ./build/jing.jar /path/to/doc-base/docbook/docbook-v5.2-os/rng/docbookxi.rng /path/to/doc-base/.manual.xml' . PHP_EOL
+    //    . 'command to check why the RelaxNG schema failed.' . PHP_EOL;
 
     // Exit normally when don't care about validation
     if ($ac["FORCE_DOM_SAVE"] == "yes") {

install-unix.xml.in

@@ -1,6 +1,5 @@
 <?xml version='1.0' encoding='UTF-8' ?>
-<!DOCTYPE set PUBLIC "-//OASIS//DTD DocBook XML V5.0//EN"
-"./docbook/docbook-xml/docbook.dtd" [
+<!DOCTYPE PHPDOC [
 
 <!ENTITY % language-defs     SYSTEM "../@LANGDIR@/language-defs.ent">
 <!ENTITY % language-snippets SYSTEM "../@LANGDIR@/language-snippets.ent">
@@ -21,7 +20,7 @@
 
 ]>
 
-<book xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="install" xml:lang="en" xmlns:xlink="http://www.w3.org/1999/xlink">
+<book xmlns="http://docbook.org/ns/docbook" version="5.2" xml:id="install" xml:lang="en" xmlns:xlink="http://www.w3.org/1999/xlink">
  <title>Installing PHP</title>
  <preface>
   <title>Preface</title>

install-win.xml.in

@@ -1,6 +1,5 @@
 <?xml version='1.0' encoding='UTF-8' ?>
-<!DOCTYPE set PUBLIC "-//OASIS//DTD DocBook XML V5.0//EN"
-"./docbook/docbook-xml/docbook.dtd" [
+<!DOCTYPE PHPDOC [
 
 <!ENTITY % language-defs     SYSTEM "../@LANGDIR@/language-defs.ent">
 <!ENTITY % language-snippets SYSTEM "../@LANGDIR@/language-snippets.ent">
@@ -26,7 +25,7 @@
      en/install/windows/index.xml file to build this file -->
 
 
-<book id="install" lang="en">
+<book xmlns="http://docbook.org/ns/docbook" version="5.2" xml:id="install" xml:lang="en">
 <title>Installation on Windows systems</title>
   <para>
   Installing PHP on modern Microsoft Windows systems and recommended configuration with common web servers.

manual.xml.in

@@ -1,9 +1,5 @@
 <?xml version='1.0' encoding='@ENCODING@' ?>
-<!DOCTYPE set PUBLIC "-//OASIS//DTD DocBook XML V5.0//EN"
-"./docbook/docbook-xml/docbook.dtd" [
-
-<!-- $Revision$ -->
-
+<!DOCTYPE PHPDOC [
 <!-- Add translated specific definitions and snippets -->
 @TRANSLATION_ONLY_INCL_BEGIN@
 <!ENTITY % language-defs     SYSTEM "../@LANGDIR@/language-defs.ent">
@@ -37,7 +33,7 @@
 %frontpage.entities;
 ]>
 
-<set xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="index" xml:lang="@LANG@" xmlns:xlink="http://www.w3.org/1999/xlink">
+<set xmlns="http://docbook.org/ns/docbook" version="5.2" xml:id="index" xml:lang="@LANG@" xmlns:xlink="http://www.w3.org/1999/xlink">
  <title>&PHPManual;</title>
  &bookinfo;