Bugzilla 48380: Avoid ClassCastException when using fox:widow-content-limit

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1056513 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 97 insertions, 47 deletions

diff --git a/src/java/org/apache/fop/layoutmgr/ElementListUtils.java b/src/java/org/apache/fop/layoutmgr/ElementListUtils.java
index 6a843ac63..2bd6f429a 100644
--- a/src/java/org/apache/fop/layoutmgr/ElementListUtils.java
+++ b/src/java/org/apache/fop/layoutmgr/ElementListUtils.java
@@ -55,43 +55,7 @@ public final class ElementListUtils {
      * @return true if the constraint is bigger than the list contents
      */
     public static boolean removeLegalBreaks(List elements, int constraint) {
-        int len = 0;
-        ListIterator iter = elements.listIterator();
-        while (iter.hasNext()) {
-            ListElement el = (ListElement)iter.next();
-            if (el.isPenalty()) {
-                KnuthPenalty penalty = (KnuthPenalty)el;
-                //Convert all penalties to break inhibitors
-                if (penalty.getPenalty() < KnuthPenalty.INFINITE) {
-                    iter.set(new KnuthPenalty(penalty.getWidth(), KnuthPenalty.INFINITE,
-                            penalty.isPenaltyFlagged(), penalty.getPosition(),
-                            penalty.isAuxiliary()));
-                }
-            } else if (el.isGlue()) {
-                KnuthGlue glue = (KnuthGlue)el;
-                len += glue.getWidth();
-                iter.previous();
-                el = (ListElement)iter.previous();
-                iter.next();
-                if (el.isBox()) {
-                    iter.add(new KnuthPenalty(0, KnuthPenalty.INFINITE, false,
-                            null, false));
-                }
-                iter.next();
-            } else if (el instanceof BreakElement) {
-                BreakElement breakEl = (BreakElement)el;
-                if (breakEl.getPenaltyValue() < KnuthPenalty.INFINITE) {
-                    breakEl.setPenaltyValue(KnuthPenalty.INFINITE);
-                }
-            } else {
-                KnuthElement kel = (KnuthElement)el;
-                len += kel.getWidth();
-            }
-            if (len >= constraint) {
-                return false;
-            }
-        }
-        return true;
+        return removeLegalBreaks(elements, constraint, false);
     }
 
     /**
@@ -103,27 +67,48 @@ public final class ElementListUtils {
      * @return true if the constraint is bigger than the list contents
      */
     public static boolean removeLegalBreaksFromEnd(List elements, int constraint) {
+        return removeLegalBreaks(elements, constraint, true);
+    }
+
+    private static boolean removeLegalBreaks(List elements, int constraint, boolean fromEnd) {
+
         int len = 0;
-        ListIterator i = elements.listIterator(elements.size());
-        while (i.hasPrevious()) {
-            ListElement el = (ListElement)i.previous();
+        ListElement el;
+
+        for (ListIterator iter = elements.listIterator(fromEnd ? elements.size() : 0);
+                (fromEnd ? iter.hasPrevious() : iter.hasNext());) {
+
+            if (fromEnd) {
+                el = (ListElement) iter.previous();
+            } else {
+                el = (ListElement) iter.next();
+            }
+
             if (el.isPenalty()) {
                 KnuthPenalty penalty = (KnuthPenalty)el;
-                //Convert all penalties to break inhibitors
+                //Convert penalty to break inhibitor
                 if (penalty.getPenalty() < KnuthPenalty.INFINITE) {
-                    i.set(new KnuthPenalty(penalty.getWidth(), KnuthPenalty.INFINITE,
+                    iter.set(new KnuthPenalty(penalty.getWidth(), KnuthPenalty.INFINITE,
                             penalty.isPenaltyFlagged(), penalty.getPosition(),
                             penalty.isAuxiliary()));
                 }
             } else if (el.isGlue()) {
                 KnuthGlue glue = (KnuthGlue)el;
                 len += glue.getWidth();
-                el = (ListElement)i.previous();
-                i.next();
+                //check if previous is a box
+                if (!fromEnd) {
+                    iter.previous();
+                }
+                el = (ListElement)iter.previous();
+                iter.next();
                 if (el.isBox()) {
-                    i.add(new KnuthPenalty(0, KnuthPenalty.INFINITE, false,
+                    //add break inhibitor
+                    iter.add(new KnuthPenalty(0, KnuthPenalty.INFINITE, false,
                             null, false));
                 }
+                if (!fromEnd) {
+                    iter.next();
+                }
             } else if (el.isUnresolvedElement()) {
                 if (el instanceof BreakElement) {
                     BreakElement breakEl = (BreakElement)el;
@@ -138,10 +123,12 @@ public final class ElementListUtils {
                 KnuthElement kel = (KnuthElement)el;
                 len += kel.getWidth();
             }
+
             if (len >= constraint) {
                 return false;
             }
         }
+
         return true;
     }
 
@@ -191,8 +178,7 @@ public final class ElementListUtils {
      * @return true if the list ends with a forced break
      */
     public static boolean endsWithForcedBreak(List elems) {
-        ListElement last = (ListElement) ListUtil.getLast(elems);
-        return last.isForcedBreak();
+        return ((ListElement) ListUtil.getLast(elems)).isForcedBreak();
     }
 
     /**
diff --git a/status.xml b/status.xml
index 2f2608cfd..16ef4dfe6 100644
--- a/status.xml
+++ b/status.xml
@@ -58,6 +58,9 @@
       documents. Example: the fix of marks layering will be such a case when it's done.
     -->
     <release version="FOP Trunk" date="TBD">
+      <action context="Layout" dev="AD" type="fix" fixes-bug="48380">
+        Bugfix: avoid ClassCastException when using fox:widow-content-limit
+      </action>
       <action context="Layout" dev="VH" type="fix" fixes-bug="50089">
         Bugfix: content after forced break in block-container is not rendered.
       </action>
diff --git a/test/layoutengine/standard-testcases/fox_widow-content-limit_bug48380.xml b/test/layoutengine/standard-testcases/fox_widow-content-limit_bug48380.xml
new file mode 100644
index 000000000..7dab0b3af
--- /dev/null
+++ b/test/layoutengine/standard-testcases/fox_widow-content-limit_bug48380.xml
@@ -0,0 +1,61 @@
+<?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>

+      Check for bug 48380: ClassCastException when using fox:widow-content-limit.

+    </p>

+  </info>

+  <fo>

+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:fox="http://xmlgraphics.apache.org/fop/extensions">

+      <fo:layout-master-set>

+        <fo:simple-page-master master-name="normal" page-width="210mm" page-height="297mm">

+          <fo:region-body/>

+        </fo:simple-page-master>

+      </fo:layout-master-set>

+      <fo:page-sequence master-reference="normal" white-space-collapse="true">

+        <fo:flow flow-name="xsl-region-body">

+          <fo:table fox:orphan-content-limit="4em" fox:widow-content-limit="4em" table-layout="fixed" width="100%">

+            <fo:table-body>

+              <fo:table-row>

+                <fo:table-cell>

+                  <fo:block>

+                    <fo:list-block space-after="6pt">

+                      <fo:list-item>

+                        <fo:list-item-label>

+                          <fo:block>.</fo:block>

+                        </fo:list-item-label>

+                        <fo:list-item-body>

+                          <fo:block start-indent="1cm">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>

+    <!-- Run only basic checks; should not throw a ClassCastException -->

+  </checks>

+</testcase>
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