Bugzilla #54167: Disable the overflow recovery mechanism when the flow IPD changes

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1411306 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/layoutmgr/BreakingAlgorithm.java

@@ -460,6 +460,10 @@ public abstract class BreakingAlgorithm {
         return this.partOverflowRecoveryActivated;
     }
 
+    protected KnuthNode getLastTooLong() {
+        return lastTooLong;
+    }
+
     /**
      * Empty method, hook for subclasses. Called before determining the optimal
      * breakpoints corresponding to a given active node.

src/java/org/apache/fop/layoutmgr/PageBreakingAlgorithm.java

@@ -1108,6 +1108,19 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
 
     }
 
+    @Override
+    protected KnuthNode recoverFromOverflow() {
+        if (compareIPDs(getLastTooLong().line - 1) != 0) {
+            /**
+             * If the IPD of the next page changes, disable the recovery mechanism as the
+             * inline content has to be re-laid out according to the new IPD anyway.
+             */
+            return getLastTooLong();
+        } else {
+            return super.recoverFromOverflow();
+        }
+    }
+
     /** {@inheritDoc} */
     @Override
     protected int getIPDdifference() {

test/layoutengine/standard-testcases/flow_changing-ipd_overflow.xml

@@ -0,0 +1,58 @@
+<?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>
+      The overflow recovery mechanism must be disabled when the flow IPD changes.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="first-page"
+          page-height="120pt" page-width="220pt" margin="10pt">
+          <fo:region-body/>
+        </fo:simple-page-master>
+        <fo:simple-page-master master-name="page"
+          page-height="120pt" page-width="120pt" margin="10pt">
+          <fo:region-body/>
+        </fo:simple-page-master>
+        <fo:page-sequence-master master-name="pages">
+          <fo:repeatable-page-master-alternatives>
+            <fo:conditional-page-master-reference page-position="first" master-reference="first-page"/>
+            <fo:conditional-page-master-reference master-reference="page"/>
+          </fo:repeatable-page-master-alternatives>
+        </fo:page-sequence-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="pages">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block-container height="110pt" background-color="#F0F0F0">
+            <fo:block>This block-container overflows the page.</fo:block>
+          </fo:block-container>
+          <fo:block>After the big block-container.</fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <eval expected="2" xpath="count(//pageViewport)"/>
+    <eval expected="This block-container overflows the" xpath="//pageViewport[1]//lineArea[1]"/>
+    <eval expected="After the big" xpath="//pageViewport[2]//lineArea[1]"/>
+  </checks>
+</testcase>