Bugzilla #37828:

Bugfix for column balancing with large amounts of text.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@355042 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 82 insertions, 1 deletions

diff --git a/src/java/org/apache/fop/layoutmgr/PageSequenceLayoutManager.java b/src/java/org/apache/fop/layoutmgr/PageSequenceLayoutManager.java
index 9bc09c2f5..59d331028 100644
--- a/src/java/org/apache/fop/layoutmgr/PageSequenceLayoutManager.java
+++ b/src/java/org/apache/fop/layoutmgr/PageSequenceLayoutManager.java
@@ -349,6 +349,8 @@ public class PageSequenceLayoutManager extends AbstractLayoutManager {
                 AbstractBreaker.log.debug("restart: iOptPageCount= " + iOptPageCount
                         + " pageBreaks.size()= " + algRestart.getPageBreaks().size());
                 if (iOptPageCount > getCurrentPV().getBodyRegion().getColumnCount()) {
+                    AbstractBreaker.log.warn(
+                            "Breaking algorithm produced more columns than are available.");
                     /* reenable when everything works
                     throw new IllegalStateException(
                             "Breaking algorithm must not produce more columns than available.");
@@ -787,7 +789,7 @@ public class PageSequenceLayoutManager extends AbstractLayoutManager {
             PageViewport pv = getPageViewport(
                     false, pageIndex, RELTO_CURRENT_ELEMENT_LIST);
             while (idx < partCount) {
-                if ((idx < partCount - 1) && (colIndex >= pv.getCurrentSpan().getColumnCount())) {
+                if ((colIndex >= pv.getCurrentSpan().getColumnCount())) {
                     colIndex = 0;
                     pageIndex++;
                     pv = getPageViewport(
diff --git a/status.xml b/status.xml
index c05434c7c..8f1584344 100644
--- a/status.xml
+++ b/status.xml
@@ -27,6 +27,16 @@
 
   <changes>
     <release version="FOP Trunk">
+      <action context="Code" dev="JM" type="fix" fixes-bug="37828">
+        Bugfix: Column balancing produced strange break decisions in certain multi-column
+        documents with large amounts of text.
+      </action>
+      <action context="Code" dev="JM" type="add">
+        Added an alternative set of rules for calculating text indents which tries to mimic
+        the behaviour of many commercial FO implementations that chose to break the rules
+        in the FO specification in order to better meet the natural expectations of 
+        inexperienced FO users.
+      </action>
       <action context="Code" dev="JM" type="fix" fixes-bug="37815" due-to="Tom Craddock">
         Bugfix: The combination of content-width="scale-to-fit" and content-height="100%"
         did not work as expected due to a datatype conversion bug.
diff --git a/test/layoutengine/standard-testcases/region-body_column-count_bug37828.xml b/test/layoutengine/standard-testcases/region-body_column-count_bug37828.xml
new file mode 100644
index 000000000..add696573
--- /dev/null
+++ b/test/layoutengine/standard-testcases/region-body_column-count_bug37828.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright 2005 The Apache Software Foundation
+
+  Licensed 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 multi-column documents. Checks a problem described in Bugzilla #37828.
+      A problem with column balancing and large amounts of text.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="normal" page-width="320pt" page-height="1in">
+          <fo:region-body column-count="2" column-gap="10pt"/>
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="normal">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block span="all">
+            <fo:block>This line is spanned over all columns.</fo:block>
+          </fo:block>
+          <fo:block>
+            <fo:block>line1</fo:block>
+            <fo:block>line2</fo:block>
+            <fo:block>line3</fo:block>
+            <fo:block>line4</fo:block>
+            <fo:block>line5</fo:block>
+            <fo:block>line6</fo:block>
+            <fo:block>line7</fo:block>
+            <fo:block>line8</fo:block>
+            <fo:block>line9</fo:block>
+            <fo:block>line10</fo:block>
+          </fo:block>
+          <fo:block span="all">
+            <fo:block>This line is spanned over all columns.</fo:block>
+          </fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <eval expected="2" xpath="count(//pageViewport)"/>
+
+    <eval expected="14400" xpath="//pageViewport[@nr=1]/page/regionViewport/regionBody/mainReference/span[1]/@bpd"/>
+    <eval expected="57600" xpath="//pageViewport[@nr=1]/page/regionViewport/regionBody/mainReference/span[2]/@bpd"/>
+    <eval expected="57600" xpath="//pageViewport[@nr=1]/page/regionViewport/regionBody/mainReference/span[2]/flow[1]/@bpd"/>
+    <eval expected="57600" xpath="//pageViewport[@nr=1]/page/regionViewport/regionBody/mainReference/span[2]/flow[2]/@bpd"/>
+
+    <eval expected="14400" xpath="//pageViewport[@nr=2]/page/regionViewport/regionBody/mainReference/span[1]/@bpd"/>
+    <eval expected="14400" xpath="//pageViewport[@nr=2]/page/regionViewport/regionBody/mainReference/span[1]/flow[1]/@bpd"/>
+    <eval expected="14400" xpath="//pageViewport[@nr=2]/page/regionViewport/regionBody/mainReference/span[1]/flow[2]/@bpd"/>
+    <eval expected="14400" xpath="//pageViewport[@nr=2]/page/regionViewport/regionBody/mainReference/span[2]/@bpd"/>
+  </checks>
+</testcase>