Avoid an NPE in InlineStackingLM.applyChanges for Knuth elements with a null position; resolves bug 50276

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1043871 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/layoutmgr/inline/InlineStackingLayoutManager.java

@@ -285,8 +285,9 @@ public abstract class InlineStackingLayoutManager extends AbstractLayoutManager
         KnuthElement oldElement;
         while (oldListIterator.hasNext()) {
             oldElement = (KnuthElement) oldListIterator.next();
-            oldElement.setPosition
-                (oldElement.getPosition().getPosition());
+            if (oldElement.getPosition() != null) {
+                oldElement.setPosition(oldElement.getPosition().getPosition());
+            }
         }
         // reset the iterator
         oldListIterator = oldList.listIterator();

test/layoutengine/standard-testcases/knuth_element-null_position.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You 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.
+-->
+<!-- $Id$ -->
+<testcase>
+  <info>
+	<p>This check tests that Knuth elements with a null position do
+not cause a NPE (in InlineStackingLM.applyChanges)</p>
+  </info>
+  <fo>
+	<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:fox="http://xmlgraphics.apache.org/fop/extensions" hyphenate="true" language="de">
+	  <fo:layout-master-set>
+		<fo:simple-page-master master-name="A4" page-height="29.7cm" page-width="21cm" margin="2cm">
+		  <fo:region-body/>
+		</fo:simple-page-master>
+	  </fo:layout-master-set>
+
+	  <fo:page-sequence master-reference="A4">
+
+		<fo:flow flow-name="xsl-region-body">
+		  <fo:block><fo:inline padding-left="1cm"><fo:basic-link internal-destination="N1003F">Abluftanlage</fo:basic-link></fo:inline></fo:block>
+		  <fo:block id="N1003F"/>
+		</fo:flow>
+	  </fo:page-sequence>
+	</fo:root>
+  </fo>
+  <checks>
+    <eval expected="Abluftanlage" xpath="//flow/block/lineArea/inlineparent/inlineparent/text/word"/>
+  </checks>
+</testcase>