#1321 CPD format XML fails with NullPointer

pmd-core/src/main/java/net/sourceforge/pmd/cpd/XMLRenderer.java

@@ -32,15 +32,19 @@ public final class XMLRenderer implements Renderer {
 	 * Creates a XML Renderer with the default (platform dependent) encoding.
 	 */
 	public XMLRenderer() {
-		this(System.getProperty("file.encoding"));
+		this(null);
 	}
 
 	/**
 	 * Creates a XML Renderer with a specific output encoding.
-	 * @param encoding the encoding to use
+	 * @param encoding the encoding to use or null. If null, default (platform dependent) encoding is used.
 	 */
 	public XMLRenderer(String encoding) {
-		this.encoding = encoding;
+	    if (encoding != null) {
+	        this.encoding = encoding;
+	    } else {
+	        this.encoding = System.getProperty("file.encoding");
+	    }
 	}
 
 	private Document createDocument() {

pmd-java/src/test/java/net/sourceforge/pmd/cpd/CPDCommandLineInterfaceTest.java

@@ -9,9 +9,8 @@ import java.io.PrintStream;
 import java.io.UnsupportedEncodingException;
 import java.util.regex.Pattern;
 
-import junit.framework.Assert;
-
 import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -105,6 +104,16 @@ public class CPDCommandLineInterfaceTest {
         Assert.assertTrue(out.contains("Found a 5 line (13 tokens) duplication"));
     }
 
+    @Test
+    public void testFormatXmlWithoutEncoding() throws Exception {
+        runCPD("--minimum-tokens", "10",
+               "--language", "java",
+               "--files", "src/test/resources/net/sourceforge/pmd/cpd/clitest/",
+               "--format", "xml");
+        String out = bufferStdout.toString("UTF-8");
+        Assert.assertTrue(out.contains("<duplication lines=\"3\" tokens=\"10\">"));
+    }
+
     private void runCPD(String... args) {
         System.setProperty(CPDCommandLineInterface.NO_EXIT_AFTER_RUN, "true");
         CPD.main(args);

src/site/markdown/overview/changelog.md

@@ -81,6 +81,7 @@ and will be removed with the next release of PMD.
 * [#1316](https://sourceforge.net/p/pmd/bugs/1316/): Multi Rule Properties with delimiter not possible
 * [#1317](https://sourceforge.net/p/pmd/bugs/1317/): RuntimeException when parsing class with multiple lambdas
 * [#1319](https://sourceforge.net/p/pmd/bugs/1319/): PMD stops with NoClassDefFoundError (typeresolution)
+* [#1321](https://sourceforge.net/p/pmd/bugs/1321/): CPD format XML fails with NullPointer
 
 **API Changes:**