Motivation: When resolving xml-model style validations, relative href

do not work.  As this is relying on the EntityResolver, there are possibly
other relative entity resolutions which do not work either.

Solution: Added relative URI handling to the resolveURL method of Resolver
class.  Code attempts the original code path before attempting to resolve
relative URI's to preserver legacy behavior as much as possible.
 - also updated latest jxvc version.

pom.xml

@@ -163,13 +163,13 @@
     <dependency>
       <groupId>com.componentcorp.xml.validation</groupId>
       <artifactId>jxvc</artifactId>
-      <version>0.9.3</version>
+      <version>0.9.4</version>
       <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>com.componentcorp.xml.validation</groupId>
       <artifactId>relaxng-compact</artifactId>
-      <version>0.9.3</version>
+      <version>0.9.4</version>
       <scope>test</scope>
     </dependency>
     <dependency>

src/main/java/org/codehaus/mojo/xml/Resolver.java

@@ -28,6 +28,8 @@
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.parsers.SAXParserFactory;
@@ -178,7 +180,7 @@ public Source resolve( String pHref, String pBase )
 
         if ( null == url )
         {
-            url = resolve( pHref );
+            url = resolve( pHref );     //probably should call new method resolve(String,URI) but left alone for legacy reasons.
         }
 
         if ( url != null )
@@ -245,8 +247,19 @@ public LSInput resolveResource( String pType, String pNamespaceURI, String pPubl
         {
             return newLSInput( isource );
         }
+        URI baseURI = null;
+        if (pBaseURI!=null){
+            try
+            {
+                baseURI = new URI(pBaseURI);
+            }
+            catch ( URISyntaxException ex )
+            {
+                baseURI=null;   //or perhaps this should be an UndeclaredThrowableException
+            }
+        }
 
-        URL url = resolve( pSystemId );
+        URL url = resolve( pSystemId ,baseURI);
         if ( url != null )
         {
             try
@@ -305,7 +318,7 @@ private URL resolveAsFile( String pResource )
         }
     }
 
-    private URL resolveAsURL( String pResource )
+    private URL resolveAsURL( String pResource,URI baseURI )
     {
         InputStream stream = null;
         try
@@ -318,7 +331,7 @@ private URL resolveAsURL( String pResource )
         }
         catch ( IOException e )
         {
-            return null;
+            //fall through to relative URI resolution
         }
         finally
         {
@@ -334,6 +347,41 @@ private URL resolveAsURL( String pResource )
                 }
             }
         }
+        try{
+            URI resourceASURI = new URI (pResource);
+            if (baseURI!=null &&!resourceASURI.isAbsolute() && baseURI.isAbsolute()){
+                resourceASURI=baseURI.resolve( resourceASURI );
+                final URL url = resourceASURI.toURL();
+                stream = url.openStream();
+                stream.close();
+                stream = null;
+                return url;
+
+            }
+        }
+        catch ( URISyntaxException ex )
+        {
+            //ignore
+        }
+        catch ( IOException e )
+        {
+            //ignore
+        }
+        finally
+        {
+            if ( stream != null )
+            {
+                try
+                {
+                    stream.close();
+                }
+                catch ( Throwable t )
+                {
+                    // Ignore me
+                }
+            }
+        }
+        return null;
     }
 
     /**
@@ -343,6 +391,11 @@ private URL resolveAsURL( String pResource )
      */
     public URL resolve( String pResource )
     {
+        return resolve(pResource,(URI)null);
+    }
+
+
+    private URL resolve(String pResource,URI baseURI){
         if ( pResource == null )
         {
             return null;
@@ -357,7 +410,7 @@ public URL resolve( String pResource )
         URL url = resolveAsResource( pResource );
         if ( url == null )
         {
-            url = resolveAsURL( pResource );
+            url = resolveAsURL( pResource,baseURI );
             if ( url == null )
             {
                 url = resolveAsFile( pResource );
@@ -366,7 +419,7 @@ public URL resolve( String pResource )
 
         try
         {
-            return locator.getResource( pResource ).getURL();
+            return locator.getResource( url.toExternalForm()).getURL();
         }
         catch ( ResourceNotFoundException e )
         {
@@ -398,8 +451,18 @@ public InputSource resolveEntity( String pName, String pPublicId, String pBaseUR
         {
             return source;
         }
-
-        URL url = resolve( pSystemId );
+        URI baseURI = null;
+        if (pBaseURI!=null){
+            try
+            {
+                baseURI = new URI(pBaseURI);
+            }
+            catch ( URISyntaxException ex )
+            {
+                throw new SAXException("Incorrectly formatted base URI", ex);
+            }
+        }
+        URL url = resolve( pSystemId ,baseURI);
         if ( url != null )
         {
             return asInputSource( url );

src/test/it18/pom.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+   Copyright 2006 The Apache Software Foundation.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+ 
+        http://www.apache.org/licenses/LICENSE-2.0
+ 
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+-->
+<project>
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.codehaus.mojo.xml</groupId>
+  <artifactId>it15</artifactId>
+  <version>0.1</version>
+  <name>Maven XML Plugin IT 15</name>
+  <description>Integration Test 15 for the Maven XML Plugin</description>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>xml-maven-plugin</artifactId>
+        <version>0.2</version>
+        <configuration>
+          <validationSets>
+            <validationSet>
+              <dir>xml</dir>
+              <schemaLanguage>http://componentcorp.com/xml/ns/xml-model/1.0</schemaLanguage>
+            </validationSet>
+          </validationSets>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/test/it18/schema.rnc

@@ -0,0 +1,5 @@
+
+element counter { 
+
+    element item { empty }*
+}

src/test/it18/xml/doc1.xml

@@ -0,0 +1,21 @@
+<!--
+
+   Copyright 2006 The Apache Software Foundation.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+ 
+        http://www.apache.org/licenses/LICENSE-2.0
+ 
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+-->
+
+<?xml-model href="../schema.rnc" schematypens="http://www.iana.org/assignments/media-types/application/relax-ng-compact-syntax" ?>
+<counter ><item/><item/><item/></counter>
+

src/test/java/org/codehaus/mojo/xml/test/ValidateMojoTest.java

@@ -142,6 +142,23 @@ public void testIt15()
     }
 
 
+    /**
+     * Builds, and runs the it15 project.
+     * @throws Exception The test failed.
+     */
+    public void testIt18()
+        throws Exception
+    {
+        try{
+            runTest( "src/test/it18" );
+        }
+        catch(Exception e){
+            e.printStackTrace();
+            fail();
+        }
+    }
+
+
     /**
      * Builds and runs the xinclude test project
      * @throws Exception The test failed.