Submitted By: Pierre Labastie <pierre dot labastie at neuf dot fr>
Date: 2015-09-13
Origin: https://issues.apache.org/jira/browse/FOP-2461
Initial package Version: 2.0
Upstream Status: Applied
Description: Prevent a NullPointerException when "padding-after" is used in
             a "list-block" (most notably, that occurs often when rendering
             LFS to PDF).
diff -Naur fop-2.0.old/src/java/org/apache/fop/layoutmgr/AbstractBreaker.java fop-2.0.new/src/java/org/apache/fop/layoutmgr/AbstractBreaker.java
--- fop-2.0.old/src/java/org/apache/fop/layoutmgr/AbstractBreaker.java	2015-05-26 10:03:48.000000000 +0200
+++ fop-2.0.new/src/java/org/apache/fop/layoutmgr/AbstractBreaker.java	2015-09-13 09:22:33.862386032 +0200
@@ -748,6 +748,9 @@
                 positionIndex++;
                 KnuthElement element = iter.next();
                 position = element.getPosition();
+                if (position == Position.EMPTY_POS) {
+                    position = null;
+                }
                 if (element.isBox()) {
                     boxFound = true;
                     firstElements.add(element);
@@ -773,7 +776,7 @@
             do {
                 KnuthElement nextElement = iter.next();
                 position = nextElement.getPosition();
-            } while (position == null
+            } while (position == null || position == Position.EMPTY_POS
                     || position instanceof SpaceResolver.SpaceHandlingPosition
                     || position instanceof SpaceResolver.SpaceHandlingBreakPosition
                         && position.getPosition().getIndex() == -1);
diff -Naur fop-2.0.old/src/java/org/apache/fop/layoutmgr/inline/TextLayoutManager.java fop-2.0.new/src/java/org/apache/fop/layoutmgr/inline/TextLayoutManager.java
--- fop-2.0.old/src/java/org/apache/fop/layoutmgr/inline/TextLayoutManager.java	2015-05-26 10:03:48.000000000 +0200
+++ fop-2.0.new/src/java/org/apache/fop/layoutmgr/inline/TextLayoutManager.java	2015-09-13 09:22:33.866385960 +0200
@@ -210,9 +210,10 @@
         GlyphMapping lastMapping = null;
         while (posIter.hasNext()) {
             Position nextPos = posIter.next();
-            assert (nextPos instanceof LeafPosition);
-            final LeafPosition tbpNext = (LeafPosition) nextPos;
-            if (tbpNext == null) {
+            final LeafPosition tbpNext;
+            if (nextPos instanceof LeafPosition) {
+                tbpNext = (LeafPosition)nextPos;
+            } else {
                 continue; //Ignore elements without Positions
             }
             if (tbpNext.getLeafPos() != -1) {
diff -Naur fop-2.0.old/src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java fop-2.0.new/src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java
--- fop-2.0.old/src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java	2015-05-26 10:03:48.000000000 +0200
+++ fop-2.0.new/src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java	2015-09-13 09:21:18.015757311 +0200
@@ -616,7 +616,7 @@
                 }
                 lastPos = pos;
             }
-            if (pos instanceof NonLeafPosition && pos.getPosition() != null) {
+            if (pos instanceof NonLeafPosition && !isSubPositionEmpty(pos.getPosition())) {
                 // pos contains a ListItemPosition created by this ListBlockLM
                 positionList.add(pos.getPosition());
             }
@@ -697,6 +697,10 @@
         checkEndOfLayout(lastPos);
     }
 
+    private boolean isSubPositionEmpty(Position sub) {
+        return sub == Position.EMPTY_POS;
+    }
+
     /**
      * Return an Area which can contain the passed childArea. The childArea
      * may not yet have any content, but it has essential traits set.
diff -Naur fop-2.0.old/src/java/org/apache/fop/layoutmgr/ListElement.java fop-2.0.new/src/java/org/apache/fop/layoutmgr/ListElement.java
--- fop-2.0.old/src/java/org/apache/fop/layoutmgr/ListElement.java	2015-05-26 10:03:48.000000000 +0200
+++ fop-2.0.new/src/java/org/apache/fop/layoutmgr/ListElement.java	2015-09-13 09:22:33.866385960 +0200
@@ -34,7 +34,11 @@
      * @param position the Position instance needed by the addAreas stage of the LMs.
      */
     public ListElement(Position position) {
-        this.position = position;
+        if (position != null) {
+            this.position = position;
+        } else {
+            this.position = Position.EMPTY_POS;
+        }
     }
 
     /**
@@ -49,7 +53,11 @@
      * @param position the Position instance
      */
     public void setPosition(Position position) {
-        this.position = position;
+        if (position != null) {
+            this.position = position;
+        }  else {
+            this.position = Position.EMPTY_POS;
+        }
     }
 
     /**
diff -Naur fop-2.0.old/src/java/org/apache/fop/layoutmgr/Position.java fop-2.0.new/src/java/org/apache/fop/layoutmgr/Position.java
--- fop-2.0.old/src/java/org/apache/fop/layoutmgr/Position.java	2015-05-26 10:03:48.000000000 +0200
+++ fop-2.0.new/src/java/org/apache/fop/layoutmgr/Position.java	2015-09-13 09:22:33.866385960 +0200
@@ -24,6 +24,7 @@
 
     private LayoutManager layoutManager;
     private int index = -1;
+    public static final Position EMPTY_POS = new EmptyPosition();
 
     /**
      * Construct a position.
@@ -127,5 +128,11 @@
         sb.append(")");
         return sb.toString();
     }
+
+    public static final class EmptyPosition extends Position {
+        public EmptyPosition() {
+            super(null);
+        }
+    }
 }
 
diff -Naur fop-2.0.old/test/layoutengine/standard-testcases/List-item-block-padding-after.xml fop-2.0.new/test/layoutengine/standard-testcases/List-item-block-padding-after.xml
--- fop-2.0.old/test/layoutengine/standard-testcases/List-item-block-padding-after.xml	1970-01-01 01:00:00.000000000 +0100
+++ fop-2.0.new/test/layoutengine/standard-testcases/List-item-block-padding-after.xml	2015-09-13 09:22:33.866385960 +0200
@@ -0,0 +1,65 @@
+<?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 test checks that padding-after property in list block.
+    </p>
+  </info>
+  <fo>
+<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+    <fo:layout-master-set>
+        <fo:simple-page-master margin="20mm" master-name="A4" page-height="297mm" page-width="210mm">
+            <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:table table-layout="fixed" width="100%">
+				<fo:table-column column-width="proportional-column-width(1)"/>
+				<fo:table-body>
+					<fo:table-row>
+						<fo:table-cell>
+							<fo:block>
+								<fo:list-block provisional-distance-between-starts="5mm">
+									<fo:list-item>
+										<fo:list-item-label end-indent="label-end()">
+											<fo:block padding-after="1mm" padding-before="1.8mm">*</fo:block>
+										</fo:list-item-label>
+										<fo:list-item-body start-indent="body-start()">
+											<fo:block padding-after="1mm" padding-before="1.8mm"> test </fo:block>
+										</fo:list-item-body>
+									</fo:list-item>
+								</fo:list-block>
+							</fo:block>
+						</fo:table-cell>
+					</fo:table-row>
+				</fo:table-body>
+			</fo:table>
+        </fo:flow>
+    </fo:page-sequence>
+</fo:root>
+ </fo>
+  <checks>
+      <eval expected="2834" xpath="//flow/block/block/block/block/block/block[1]/block/@padding-after"/>
+      <eval expected="5102" xpath="//flow/block/block/block/block/block/block[1]/block/@padding-before"/>
+      <eval expected="2834" xpath="//flow/block/block/block/block/block/block[1]/block/@padding-after"/>
+      <eval expected="5102" xpath="//flow/block/block/block/block/block/block[1]/block/@padding-before"/>
+  </checks>
+</testcase>