From 5ce5fe50a74b9e3f84cabcffee46f860c86dbd47 Mon Sep 17 00:00:00 2001
From: Simon Steiner <ssteiner@apache.org>
Date: Thu, 22 Apr 2021 10:45:11 +0000
Subject: [PATCH] FOP-3008: Table with linefeed-treatment may give
 ClassCastException

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1889102 13f79535-47bb-0310-9956-ffa450edef68
---
 .../java/org/apache/fop/fo/flow/Wrapper.java  |  2 +-
 .../fop/layoutmgr/AreaAdditionUtil.java       |  2 +-
 .../layoutmgr/BlockStackingLayoutManager.java |  4 +-
 .../fop/layoutmgr/ElementListUtils.java       |  3 +-
 .../apache/fop/layoutmgr/KnuthPenalty.java    |  4 +-
 .../java/org/apache/fop/util/ListUtil.java    | 10 ++++
 .../standard-testcases/table_linefeed.xml     | 57 +++++++++++++++++++
 7 files changed, 76 insertions(+), 6 deletions(-)
 create mode 100644 fop/test/layoutengine/standard-testcases/table_linefeed.xml

diff --git a/fop-core/src/main/java/org/apache/fop/fo/flow/Wrapper.java b/fop-core/src/main/java/org/apache/fop/fo/flow/Wrapper.java
index 39f472cbb..809125088 100644
--- a/fop-core/src/main/java/org/apache/fop/fo/flow/Wrapper.java
+++ b/fop-core/src/main/java/org/apache/fop/fo/flow/Wrapper.java
@@ -121,7 +121,7 @@ public class Wrapper extends FObjMixed implements CommonAccessibilityHolder {
             while (ancestor.getNameId() == Constants.FO_WRAPPER) {
                 ancestor = ancestor.getParent();
             }
-            if (!(ancestor instanceof FObjMixed)) {
+            if (!(ancestor instanceof FObjMixed) && !child.toString().trim().isEmpty()) {
                 invalidChildError(
                         getLocator(),
                         getLocalName(),
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/AreaAdditionUtil.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/AreaAdditionUtil.java
index d731ab62a..e341078de 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/AreaAdditionUtil.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/AreaAdditionUtil.java
@@ -65,7 +65,7 @@ public final class AreaAdditionUtil {
                 }
                 lastPos = pos;
             }
-            if (pos instanceof NonLeafPosition) {
+            if (pos instanceof NonLeafPosition && pos.getPosition() != null) {
                 // pos was created by a child of this FlowLM
                 positionList.add(pos.getPosition());
                 lastLM = (pos.getPosition().getLM());
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockStackingLayoutManager.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockStackingLayoutManager.java
index 4dddbcf11..1e55edd07 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockStackingLayoutManager.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockStackingLayoutManager.java
@@ -535,8 +535,8 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
             return;
         }
 
-        ListElement last = ListUtil.getLast(contentList);
-        if (last.isGlue()) {
+        ListElement last = ListUtil.getLastListElement(contentList);
+        if (last == null || last.isGlue()) {
             // the last element in contentList is a glue;
             // it is a feasible breakpoint, there is no need to add
             // a penalty
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/ElementListUtils.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/ElementListUtils.java
index 9b964843e..3920481e7 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/ElementListUtils.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/ElementListUtils.java
@@ -178,7 +178,8 @@ public final class ElementListUtils {
      * @return true if the list ends with a forced break
      */
     public static boolean endsWithForcedBreak(List elems) {
-        return ((ListElement) ListUtil.getLast(elems)).isForcedBreak();
+        ListElement last = ListUtil.getLastListElement(elems);
+        return last == null || last.isForcedBreak();
     }
 
     /**
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/KnuthPenalty.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/KnuthPenalty.java
index 220f9c35d..c80cb389b 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/KnuthPenalty.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/KnuthPenalty.java
@@ -19,6 +19,8 @@
 
 package org.apache.fop.layoutmgr;
 
+import org.apache.fop.fo.Constants;
+
 /**
  * An instance of this class represents information about a feasible
  * breaking point; it does not represent any piece of content.
@@ -47,7 +49,7 @@ public class KnuthPenalty extends KnuthElement {
 
     private int penalty;
     private boolean penaltyFlagged;
-    private int breakClass = -1;
+    private int breakClass = Constants.EN_AUTO;
 
     /**
      * Create a new KnuthPenalty.
diff --git a/fop-core/src/main/java/org/apache/fop/util/ListUtil.java b/fop-core/src/main/java/org/apache/fop/util/ListUtil.java
index 8e88e4cbf..45af2b5c3 100644
--- a/fop-core/src/main/java/org/apache/fop/util/ListUtil.java
+++ b/fop-core/src/main/java/org/apache/fop/util/ListUtil.java
@@ -21,6 +21,8 @@ package org.apache.fop.util;
 
 import java.util.List;
 
+import org.apache.fop.layoutmgr.ListElement;
+
 /**
  * Provides helper functions for {@link java.util.List}.
  *
@@ -42,6 +44,14 @@ public final class ListUtil {
         return list.get(list.size() - 1);
     }
 
+    public static ListElement getLastListElement(List list) {
+        Object last = getLast(list);
+        if (last instanceof ListElement) {
+            return (ListElement) last;
+        }
+        return null;
+    }
+
     /**
      * Retrieve and remove the last element from a list.
      *
diff --git a/fop/test/layoutengine/standard-testcases/table_linefeed.xml b/fop/test/layoutengine/standard-testcases/table_linefeed.xml
new file mode 100644
index 000000000..0486e51b2
--- /dev/null
+++ b/fop/test/layoutengine/standard-testcases/table_linefeed.xml
@@ -0,0 +1,57 @@
+<?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 table linefeed in certain situations.
+    </p>
+  </info>
+  <fo>
+<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+  <fo:layout-master-set>
+    <fo:simple-page-master master-name="ref" page-height="297.0mm" page-width="210.0mm">
+      <fo:region-body region-name="xsl-region-body" />
+    </fo:simple-page-master>
+    <fo:page-sequence-master master-name="master">
+      <fo:repeatable-page-master-reference master-reference="ref" maximum-repeats="99999" />
+    </fo:page-sequence-master>
+  </fo:layout-master-set>
+  <fo:page-sequence master-reference="master">
+    <fo:flow flow-name="xsl-region-body" linefeed-treatment="preserve">
+      <fo:block>
+        <fo:table table-layout="fixed" >
+          <fo:table-column column-width="226pt" />          
+          <fo:table-body >
+            <fo:table-row>
+              <fo:table-cell >
+                <fo:wrapper>
+                </fo:wrapper>
+              </fo:table-cell>
+            </fo:table-row>
+          </fo:table-body>
+        </fo:table>
+      </fo:block>
+    </fo:flow>
+  </fo:page-sequence>
+</fo:root>
+  </fo>
+  <checks>
+    <eval expected="595275" xpath="//lineArea[1]/@ipd"/>
+  </checks>
+</testcase>
-- 
2.39.5