FOP-3105: Infinite loop when using page break with changing ipd

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1904996 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 15 insertions, 6 deletions

diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockLayoutManager.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockLayoutManager.java
index ac0da5f6a..92fac64c4 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockLayoutManager.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/BlockLayoutManager.java
@@ -141,7 +141,9 @@ public class BlockLayoutManager extends SpacedBorderedPaddedBlockLayoutManager
             return childLM.getNextKnuthElements(childLC, alignment);
         } else {
             if (childLM instanceof LineLayoutManager) {
-                assert (restartPosition instanceof LeafPosition);
+                if (!(restartPosition instanceof LeafPosition)) {
+                    restartPosition = null;
+                }
                 return ((LineLayoutManager) childLM).getNextKnuthElements(childLC, alignment,
                         (LeafPosition) restartPosition);
             } else {
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/RestartAtLM.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/RestartAtLM.java
index 9c8aa8252..6dd80075d 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/RestartAtLM.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/RestartAtLM.java
@@ -92,8 +92,10 @@ class RestartAtLM {
                     position = position.getPosition();
                 }
                 if (position.getPosition() == null) {
-                    position.getLM().getFObj().setForceKeepTogether(true);
-                    invalidPosition = true;
+                    if (!position.getLM().getFObj().isForceKeepTogether()) {
+                        position.getLM().getFObj().setForceKeepTogether(true);
+                        invalidPosition = true;
+                    }
                     return null;
                 }
                 restartAtLM = position.getPosition().getLM();
diff --git a/fop-core/src/main/java/org/apache/fop/layoutmgr/inline/LineLayoutManager.java b/fop-core/src/main/java/org/apache/fop/layoutmgr/inline/LineLayoutManager.java
index d19642ab5..60d05b581 100644
--- a/fop-core/src/main/java/org/apache/fop/layoutmgr/inline/LineLayoutManager.java
+++ b/fop-core/src/main/java/org/apache/fop/layoutmgr/inline/LineLayoutManager.java
@@ -651,8 +651,13 @@ public class LineLayoutManager extends InlineStackingLayoutManager
      */
     public List getNextKnuthElements(LayoutContext context, int alignment,
             LeafPosition restartPosition) {
-        log.trace("Restarting line breaking from index " + restartPosition.getIndex());
-        int parIndex = restartPosition.getLeafPos();
+        int parIndex = 0;
+        int restartPositionIdx = 0;
+        if (restartPosition != null) {
+            log.trace("Restarting line breaking from index " + restartPosition.getIndex());
+            parIndex = restartPosition.getLeafPos();
+            restartPositionIdx = restartPosition.getIndex();
+        }
 
         for (int i = 0; i < parIndex; i++) {
             knuthParagraphs.remove(0);
@@ -664,7 +669,7 @@ public class LineLayoutManager extends InlineStackingLayoutManager
             ((Paragraph) paragraph).ignoreAtStart = 0;
             isFirstInBlock = false;
         }
-        paragraph.subList(0, restartPosition.getIndex() + 1).clear();
+        paragraph.subList(0, restartPositionIdx + 1).clear();
         Iterator<KnuthElement> iter = paragraph.iterator();
         while (iter.hasNext() && !iter.next().isBox()) {
             iter.remove();