Remove built-in definition of xml.xsd from xmerl

Removes the built-in definitions of http://www.w3.org/2001/xml.xsd from
the xmerl_xsd module. xmerl_xsd does load the definitions of the above
schema into its processing table during initialization. This leads to
the inability to process XSD schemas that properly import xml.xsd (as
suggested in xml.xsd itself).

Furthermore, the definitions are loaded from a binary containing the
corresponding terms in Erlang external term format. Since this is not
refactoring safe the intended functionality already broke long ago
(prior to github import) because some of the record definitions did
change in releases older than R13B03.

To sum up, the current code does not do anything useful because the
built-in definitions from the binary can't be used due to incompatible
records. Thus, this fix is not backwards incompatible. The change also
adds two new test cases covering common use-cases when using 'xml:'
types in custom schemas.

3 files changed, 305 insertions, 0 deletions

diff --git a/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xml b/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xml
new file mode 100644
index 0000000000..17d7ceffee
--- /dev/null
+++ b/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<book title="Title" xml:lang="EN">
+  <author>Author1</author>
+  <author>Author2</author>
+</book>
diff --git a/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xsd b/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xsd
new file mode 100644
index 0000000000..830951ec1b
--- /dev/null
+++ b/lib/xmerl/test/xmerl_xsd_SUITE_data/book.xsd
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
+  <xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="xml.xsd"/>
+  <xs:element name="book">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element name="author" type="xs:string" maxOccurs="unbounded"/>
+      </xs:sequence>
+      <xs:attribute name="title" type="xs:string"/>
+      <xs:attribute ref="xml:lang"/>
+    </xs:complexType>
+  </xs:element>
+</xs:schema>
diff --git a/lib/xmerl/test/xmerl_xsd_SUITE_data/xml.xsd b/lib/xmerl/test/xmerl_xsd_SUITE_data/xml.xsd
new file mode 100644
index 0000000000..aea7d0db0a
--- /dev/null
+++ b/lib/xmerl/test/xmerl_xsd_SUITE_data/xml.xsd
@@ -0,0 +1,287 @@
+<?xml version='1.0'?>
+<?xml-stylesheet href="../2008/09/xsd.xsl" type="text/xsl"?>
+<xs:schema targetNamespace="http://www.w3.org/XML/1998/namespace" 
+  xmlns:xs="http://www.w3.org/2001/XMLSchema" 
+  xmlns   ="http://www.w3.org/1999/xhtml"
+  xml:lang="en">
+
+ <xs:annotation>
+  <xs:documentation>
+   <div>
+    <h1>About the XML namespace</h1>
+
+    <div class="bodytext">
+     <p>
+      This schema document describes the XML namespace, in a form
+      suitable for import by other schema documents.
+     </p>
+     <p>
+      See <a href="http://www.w3.org/XML/1998/namespace.html">
+      http://www.w3.org/XML/1998/namespace.html</a> and
+      <a href="http://www.w3.org/TR/REC-xml">
+      http://www.w3.org/TR/REC-xml</a> for information 
+      about this namespace.
+     </p>
+     <p>
+      Note that local names in this namespace are intended to be
+      defined only by the World Wide Web Consortium or its subgroups.
+      The names currently defined in this namespace are listed below.
+      They should not be used with conflicting semantics by any Working
+      Group, specification, or document instance.
+     </p>
+     <p>   
+      See further below in this document for more information about <a
+      href="#usage">how to refer to this schema document from your own
+      XSD schema documents</a> and about <a href="#nsversioning">the
+      namespace-versioning policy governing this schema document</a>.
+     </p>
+    </div>
+   </div>
+  </xs:documentation>
+ </xs:annotation>
+
+ <xs:attribute name="lang">
+  <xs:annotation>
+   <xs:documentation>
+    <div>
+     
+      <h3>lang (as an attribute name)</h3>
+      <p>
+       denotes an attribute whose value
+       is a language code for the natural language of the content of
+       any element; its value is inherited.  This name is reserved
+       by virtue of its definition in the XML specification.</p>
+     
+    </div>
+    <div>
+     <h4>Notes</h4>
+     <p>
+      Attempting to install the relevant ISO 2- and 3-letter
+      codes as the enumerated possible values is probably never
+      going to be a realistic possibility.  
+     </p>
+     <p>
+      See BCP 47 at <a href="http://www.rfc-editor.org/rfc/bcp/bcp47.txt">
+       http://www.rfc-editor.org/rfc/bcp/bcp47.txt</a>
+      and the IANA language subtag registry at
+      <a href="http://www.iana.org/assignments/language-subtag-registry">
+       http://www.iana.org/assignments/language-subtag-registry</a>
+      for further information.
+     </p>
+     <p>
+      The union allows for the 'un-declaration' of xml:lang with
+      the empty string.
+     </p>
+    </div>
+   </xs:documentation>
+  </xs:annotation>
+  <xs:simpleType>
+   <xs:union memberTypes="xs:language">
+    <xs:simpleType>    
+     <xs:restriction base="xs:string">
+      <xs:enumeration value=""/>
+     </xs:restriction>
+    </xs:simpleType>
+   </xs:union>
+  </xs:simpleType>
+ </xs:attribute>
+
+ <xs:attribute name="space">
+  <xs:annotation>
+   <xs:documentation>
+    <div>
+     
+      <h3>space (as an attribute name)</h3>
+      <p>
+       denotes an attribute whose
+       value is a keyword indicating what whitespace processing
+       discipline is intended for the content of the element; its
+       value is inherited.  This name is reserved by virtue of its
+       definition in the XML specification.</p>
+     
+    </div>
+   </xs:documentation>
+  </xs:annotation>
+  <xs:simpleType>
+   <xs:restriction base="xs:NCName">
+    <xs:enumeration value="default"/>
+    <xs:enumeration value="preserve"/>
+   </xs:restriction>
+  </xs:simpleType>
+ </xs:attribute>
+ 
+ <xs:attribute name="base" type="xs:anyURI"> <xs:annotation>
+   <xs:documentation>
+    <div>
+     
+      <h3>base (as an attribute name)</h3>
+      <p>
+       denotes an attribute whose value
+       provides a URI to be used as the base for interpreting any
+       relative URIs in the scope of the element on which it
+       appears; its value is inherited.  This name is reserved
+       by virtue of its definition in the XML Base specification.</p>
+     
+     <p>
+      See <a
+      href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a>
+      for information about this attribute.
+     </p>
+    </div>
+   </xs:documentation>
+  </xs:annotation>
+ </xs:attribute>
+ 
+ <xs:attribute name="id" type="xs:ID">
+  <xs:annotation>
+   <xs:documentation>
+    <div>
+     
+      <h3>id (as an attribute name)</h3> 
+      <p>
+       denotes an attribute whose value
+       should be interpreted as if declared to be of type ID.
+       This name is reserved by virtue of its definition in the
+       xml:id specification.</p>
+     
+     <p>
+      See <a
+      href="http://www.w3.org/TR/xml-id/">http://www.w3.org/TR/xml-id/</a>
+      for information about this attribute.
+     </p>
+    </div>
+   </xs:documentation>
+  </xs:annotation>
+ </xs:attribute>
+
+ <xs:attributeGroup name="specialAttrs">
+  <xs:attribute ref="xml:base"/>
+  <xs:attribute ref="xml:lang"/>
+  <xs:attribute ref="xml:space"/>
+  <xs:attribute ref="xml:id"/>
+ </xs:attributeGroup>
+
+ <xs:annotation>
+  <xs:documentation>
+   <div>
+   
+    <h3>Father (in any context at all)</h3> 
+
+    <div class="bodytext">
+     <p>
+      denotes Jon Bosak, the chair of 
+      the original XML Working Group.  This name is reserved by 
+      the following decision of the W3C XML Plenary and 
+      XML Coordination groups:
+     </p>
+     <blockquote>
+       <p>
+	In appreciation for his vision, leadership and
+	dedication the W3C XML Plenary on this 10th day of
+	February, 2000, reserves for Jon Bosak in perpetuity
+	the XML name "xml:Father".
+       </p>
+     </blockquote>
+    </div>
+   </div>
+  </xs:documentation>
+ </xs:annotation>
+
+ <xs:annotation>
+  <xs:documentation>
+   <div xml:id="usage" id="usage">
+    <h2><a name="usage">About this schema document</a></h2>
+
+    <div class="bodytext">
+     <p>
+      This schema defines attributes and an attribute group suitable
+      for use by schemas wishing to allow <code>xml:base</code>,
+      <code>xml:lang</code>, <code>xml:space</code> or
+      <code>xml:id</code> attributes on elements they define.
+     </p>
+     <p>
+      To enable this, such a schema must import this schema for
+      the XML namespace, e.g. as follows:
+     </p>
+     <pre>
+          &lt;schema . . .>
+           . . .
+           &lt;import namespace="http://www.w3.org/XML/1998/namespace"
+                      schemaLocation="http://www.w3.org/2001/xml.xsd"/>
+     </pre>
+     <p>
+      or
+     </p>
+     <pre>
+           &lt;import namespace="http://www.w3.org/XML/1998/namespace"
+                      schemaLocation="http://www.w3.org/2009/01/xml.xsd"/>
+     </pre>
+     <p>
+      Subsequently, qualified reference to any of the attributes or the
+      group defined below will have the desired effect, e.g.
+     </p>
+     <pre>
+          &lt;type . . .>
+           . . .
+           &lt;attributeGroup ref="xml:specialAttrs"/>
+     </pre>
+     <p>
+      will define a type which will schema-validate an instance element
+      with any of those attributes.
+     </p>
+    </div>
+   </div>
+  </xs:documentation>
+ </xs:annotation>
+
+ <xs:annotation>
+  <xs:documentation>
+   <div id="nsversioning" xml:id="nsversioning">
+    <h2><a name="nsversioning">Versioning policy for this schema document</a></h2>
+    <div class="bodytext">
+     <p>
+      In keeping with the XML Schema WG's standard versioning
+      policy, this schema document will persist at
+      <a href="http://www.w3.org/2009/01/xml.xsd">
+       http://www.w3.org/2009/01/xml.xsd</a>.
+     </p>
+     <p>
+      At the date of issue it can also be found at
+      <a href="http://www.w3.org/2001/xml.xsd">
+       http://www.w3.org/2001/xml.xsd</a>.
+     </p>
+     <p>
+      The schema document at that URI may however change in the future,
+      in order to remain compatible with the latest version of XML
+      Schema itself, or with the XML namespace itself.  In other words,
+      if the XML Schema or XML namespaces change, the version of this
+      document at <a href="http://www.w3.org/2001/xml.xsd">
+       http://www.w3.org/2001/xml.xsd 
+      </a> 
+      will change accordingly; the version at 
+      <a href="http://www.w3.org/2009/01/xml.xsd">
+       http://www.w3.org/2009/01/xml.xsd 
+      </a> 
+      will not change.
+     </p>
+     <p>
+      Previous dated (and unchanging) versions of this schema 
+      document are at:
+     </p>
+     <ul>
+      <li><a href="http://www.w3.org/2009/01/xml.xsd">
+	http://www.w3.org/2009/01/xml.xsd</a></li>
+      <li><a href="http://www.w3.org/2007/08/xml.xsd">
+	http://www.w3.org/2007/08/xml.xsd</a></li>
+      <li><a href="http://www.w3.org/2004/10/xml.xsd">
+	http://www.w3.org/2004/10/xml.xsd</a></li>
+      <li><a href="http://www.w3.org/2001/03/xml.xsd">
+	http://www.w3.org/2001/03/xml.xsd</a></li>
+     </ul>
+    </div>
+   </div>
+  </xs:documentation>
+ </xs:annotation>
+
+</xs:schema>
+