FOP-3208: Only restart line manager when there is a linebreak for blocklayout

9 files changed, 101 insertions, 20 deletions

diff --git a/fop-core/src/main/java/org/apache/fop/apps/FOUserAgent.java b/fop-core/src/main/java/org/apache/fop/apps/FOUserAgent.java
index 12707b30b..149af5c90 100644
--- a/fop-core/src/main/java/org/apache/fop/apps/FOUserAgent.java
+++ b/fop-core/src/main/java/org/apache/fop/apps/FOUserAgent.java
@@ -851,4 +851,8 @@ public class FOUserAgent {
     public boolean isLegacySkipPagePositionOnly() {
         return factory.isLegacySkipPagePositionOnly();
     }
+
+    public boolean isLegacyLastPageChangeIPD() {
+        return factory.isLegacyLastPageChangeIPD();
+    }
 }
diff --git a/fop-core/src/main/java/org/apache/fop/apps/FopConfParser.java b/fop-core/src/main/java/org/apache/fop/apps/FopConfParser.java
index f36593ed5..d3344ff77 100644
--- a/fop-core/src/main/java/org/apache/fop/apps/FopConfParser.java
+++ b/fop-core/src/main/java/org/apache/fop/apps/FopConfParser.java
@@ -60,6 +60,7 @@ public class FopConfParser {
     private static final String SIMPLE_LINE_BREAKING = "simple-line-breaking";
     private static final String SKIP_PAGE_POSITION_ONLY_ALLOWED = "skip-page-position-only-allowed";
     private static final String LEGACY_SKIP_PAGE_POSITION_ONLY = "legacy-skip-page-position-only";
+    private static final String LEGACY_LAST_PAGE_CHANGE_IPD = "legacy-last-page-change-ipd";
 
     private final Log log = LogFactory.getLog(FopConfParser.class);
 
@@ -308,6 +309,14 @@ public class FopConfParser {
                 LogUtil.handleException(log, e, false);
             }
         }
+        if (cfg.getChild(LEGACY_LAST_PAGE_CHANGE_IPD, false) != null) {
+            try {
+                fopFactoryBuilder.setLegacyLastPageChangeIPD(
+                        cfg.getChild(LEGACY_LAST_PAGE_CHANGE_IPD).getValueAsBoolean());
+            } catch (ConfigurationException e) {
+                LogUtil.handleException(log, e, false);
+            }
+        }
 
         // configure font manager
         new FontManagerConfigurator(cfg, baseURI, fopFactoryBuilder.getBaseURI(), resourceResolver)
diff --git a/fop-core/src/main/java/org/apache/fop/apps/FopFactory.java b/fop-core/src/main/java/org/apache/fop/apps/FopFactory.java
index 7696c3997..bdf789bf1 100644
--- a/fop-core/src/main/java/org/apache/fop/apps/FopFactory.java
+++ b/fop-core/src/main/java/org/apache/fop/apps/FopFactory.java
@@ -248,6 +248,10 @@ public final class FopFactory implements ImageContext {
         return config.isLegacySkipPagePositionOnly();
     }
 
+    boolean isLegacyLastPageChangeIPD() {
+        return config.isLegacyLastPageChangeIPD();
+    }
+
     /**
      * Returns a new {@link Fop} instance. FOP will be configured with a default user agent
      * instance. Use this factory method if your output type requires an output stream.
diff --git a/fop-core/src/main/java/org/apache/fop/apps/FopFactoryBuilder.java b/fop-core/src/main/java/org/apache/fop/apps/FopFactoryBuilder.java
index aa90bd544..ebb176c03 100644
--- a/fop-core/src/main/java/org/apache/fop/apps/FopFactoryBuilder.java
+++ b/fop-core/src/main/java/org/apache/fop/apps/FopFactoryBuilder.java
@@ -360,6 +360,11 @@ public final class FopFactoryBuilder {
         return this;
     }
 
+    public FopFactoryBuilder setLegacyLastPageChangeIPD(boolean b) {
+        fopFactoryConfigBuilder.setLegacyLastPageChangeIPD(b);
+        return this;
+    }
+
     public static class FopFactoryConfigImpl implements FopFactoryConfig {
 
         private final EnvironmentProfile enviro;
@@ -408,6 +413,8 @@ public final class FopFactoryBuilder {
 
         private boolean legacySkipPagePositionOnly;
 
+        private boolean legacyLastPageChangeIPD;
+
         private static final class ImageContextImpl implements ImageContext {
 
             private final FopFactoryConfig config;
@@ -540,6 +547,10 @@ public final class FopFactoryBuilder {
             return legacySkipPagePositionOnly;
         }
 
+        public boolean isLegacyLastPageChangeIPD() {
+            return legacyLastPageChangeIPD;
+        }
+
         public Map<String, String> getHyphenationPatternNames() {
             return hyphPatNames;
         }
@@ -593,6 +604,8 @@ public final class FopFactoryBuilder {
         void setSkipPagePositionOnlyAllowed(boolean b);
 
         void setLegacySkipPagePositionOnly(boolean b);
+
+        void setLegacyLastPageChangeIPD(boolean b);
     }
 
     private static final class CompletedFopFactoryConfigBuilder implements FopFactoryConfigBuilder {
@@ -692,6 +705,10 @@ public final class FopFactoryBuilder {
         public void setLegacySkipPagePositionOnly(boolean b) {
             throwIllegalStateException();
         }
+
+        public void setLegacyLastPageChangeIPD(boolean b) {
+            throwIllegalStateException();
+        }
     }
 
     private static final class ActiveFopFactoryConfigBuilder implements FopFactoryConfigBuilder {
@@ -792,6 +809,10 @@ public final class FopFactoryBuilder {
         public void setLegacySkipPagePositionOnly(boolean b) {
             config.legacySkipPagePositionOnly = b;
         }
+
+        public void setLegacyLastPageChangeIPD(boolean b) {
+            config.legacyLastPageChangeIPD = b;
+        }
     }
 
 }
diff --git a/fop-core/src/main/java/org/apache/fop/apps/FopFactoryConfig.java b/fop-core/src/main/java/org/apache/fop/apps/FopFactoryConfig.java
index a74b0437c..55dbb8671 100644
--- a/fop-core/src/main/java/org/apache/fop/apps/FopFactoryConfig.java
+++ b/fop-core/src/main/java/org/apache/fop/apps/FopFactoryConfig.java
@@ -171,6 +171,8 @@ public interface FopFactoryConfig {
 
     boolean isLegacySkipPagePositionOnly();
 
+    boolean isLegacyLastPageChangeIPD();
+
     /** @return the hyphenation pattern names */
     Map<String, String> getHyphenationPatternNames();
 
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 80b1487a4..4a0fcd885 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
@@ -23,25 +23,29 @@ import java.util.Iterator;
 import java.util.LinkedList;
 
 import org.apache.fop.events.EventBroadcaster;
-import org.apache.fop.layoutmgr.table.TableContentPosition;
+import org.apache.fop.layoutmgr.inline.LineLayoutManager;
 
 /**
  * Class to find the restart layoutmanager for changing IPD
  */
 class RestartAtLM {
     protected boolean invalidPosition;
+    private Position lineBreakPosition;
+    private int positionIndex;
 
     protected LayoutManager getRestartAtLM(AbstractBreaker breaker, PageBreakingAlgorithm alg,
                                            boolean ipdChangesOnNextPage, boolean onLastPageAndIPDChanges,
                                            boolean visitedBefore, AbstractBreaker.BlockSequence blockList, int start) {
+        lineBreakPosition = null;
         BreakingAlgorithm.KnuthNode optimalBreak = ipdChangesOnNextPage ? alg.getBestNodeBeforeIPDChange() : alg
                 .getBestNodeForLastPage();
         if (onLastPageAndIPDChanges && visitedBefore && breaker.originalRestartAtLM == null) {
             optimalBreak = null;
         }
-        int positionIndex = findPositionIndex(breaker, optimalBreak, alg, start);
-        if (breaker.positionAtBreak.getLM() instanceof BlockLayoutManager) {
-            positionIndex = findPositionIndex(breaker, optimalBreak, alg, 0);
+        findPositionIndex(breaker, optimalBreak, alg, start);
+        if (!breaker.getPageProvider().foUserAgent.isLegacyLastPageChangeIPD()
+                && breaker.positionAtBreak.getLM() instanceof BlockLayoutManager) {
+            findPositionIndexForBlockLayout(breaker, optimalBreak, alg);
         }
         if (ipdChangesOnNextPage || (breaker.positionAtBreak != null && breaker.positionAtBreak.getIndex() > -1)) {
             breaker.firstElementsForRestart = Collections.EMPTY_LIST;
@@ -116,23 +120,15 @@ class RestartAtLM {
         if (onLastPageAndIPDChanges && !visitedBefore && breaker.positionAtBreak.getPosition() != null) {
             restartAtLM = breaker.positionAtBreak.getPosition().getLM();
         }
-        findLeafPosition(breaker);
-        return restartAtLM;
-    }
-
-    private void findLeafPosition(AbstractBreaker breaker) {
-        while (breaker.positionAtBreak instanceof NonLeafPosition) {
-            Position pos = breaker.positionAtBreak.getPosition();
-            if (pos instanceof TableContentPosition) {
-                break;
-            }
-            breaker.positionAtBreak = pos;
+        if (lineBreakPosition != null && restartAtLM instanceof BlockLayoutManager) {
+            breaker.positionAtBreak = lineBreakPosition;
         }
+        return restartAtLM;
     }
 
-    private int findPositionIndex(AbstractBreaker breaker, BreakingAlgorithm.KnuthNode optimalBreak,
+    private void findPositionIndex(AbstractBreaker breaker, BreakingAlgorithm.KnuthNode optimalBreak,
                                   PageBreakingAlgorithm alg, int start) {
-        int positionIndex = (optimalBreak != null) ? optimalBreak.position : start;
+        positionIndex = (optimalBreak != null) ? optimalBreak.position : start;
         for (int i = positionIndex; i < alg.par.size(); i++) {
             KnuthElement elementAtBreak = alg.getElement(i);
             if (elementAtBreak.getPosition() == null) {
@@ -142,9 +138,40 @@ class RestartAtLM {
             /* Retrieve the original position wrapped into this space position */
             breaker.positionAtBreak = breaker.positionAtBreak.getPosition();
             if (breaker.positionAtBreak != null) {
-                return i;
+                this.positionIndex = i;
+                return;
+            }
+        }
+    }
+
+    private void findPositionIndexForBlockLayout(AbstractBreaker breaker, BreakingAlgorithm.KnuthNode optimalBreak,
+                                  PageBreakingAlgorithm alg) {
+        int positionIndex = (optimalBreak != null) ? optimalBreak.position : 0;
+        for (int i = positionIndex; i < alg.par.size(); i++) {
+            KnuthElement elementAtBreak = alg.getElement(i);
+            if (elementAtBreak.getPosition() == null) {
+                elementAtBreak = alg.getElement(0);
+            }
+            Position positionAtBreak = elementAtBreak.getPosition();
+            /* Retrieve the original position wrapped into this space position */
+            positionAtBreak = positionAtBreak.getPosition();
+            if (positionAtBreak != null) {
+                findLineBreakPosition(positionAtBreak);
+                if (lineBreakPosition != null) {
+                    breaker.positionAtBreak = positionAtBreak;
+                    this.positionIndex = i;
+                }
+                break;
+            }
+        }
+    }
+
+    private void findLineBreakPosition(Position positionAtBreak) {
+        while (positionAtBreak instanceof NonLeafPosition) {
+            positionAtBreak = positionAtBreak.getPosition();
+            if (positionAtBreak instanceof LineLayoutManager.LineBreakPosition) {
+                lineBreakPosition = positionAtBreak;
             }
         }
-        return positionIndex;
     }
 }
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 2fff6c494..25b68842c 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
@@ -108,7 +108,7 @@ public class LineLayoutManager extends InlineStackingLayoutManager
      * Each value holds the start and end indexes into a List of
      * inline break positions.
      */
-    static class LineBreakPosition extends LeafPosition {
+    public static class LineBreakPosition extends LeafPosition {
         private final int parIndex; // index of the Paragraph this Position refers to
         private final int startIndex; //index of the first element this Position refers to
         private final int availableShrink;
diff --git a/fop-core/src/test/java/org/apache/fop/apps/MutableConfig.java b/fop-core/src/test/java/org/apache/fop/apps/MutableConfig.java
index 17348a2e6..3fcaa4fbc 100644
--- a/fop-core/src/test/java/org/apache/fop/apps/MutableConfig.java
+++ b/fop-core/src/test/java/org/apache/fop/apps/MutableConfig.java
@@ -149,6 +149,10 @@ public final class MutableConfig implements FopFactoryConfig {
         return delegate.isLegacySkipPagePositionOnly();
     }
 
+    public boolean isLegacyLastPageChangeIPD() {
+        return delegate.isLegacyLastPageChangeIPD();
+    }
+
     public Map<String, String> getHyphenationPatternNames() {
         return delegate.getHyphenationPatternNames();
     }
diff --git a/fop-core/src/test/java/org/apache/fop/intermediate/TestAssistant.java b/fop-core/src/test/java/org/apache/fop/intermediate/TestAssistant.java
index 8b5aad6c2..f87905772 100644
--- a/fop-core/src/test/java/org/apache/fop/intermediate/TestAssistant.java
+++ b/fop-core/src/test/java/org/apache/fop/intermediate/TestAssistant.java
@@ -127,6 +127,7 @@ public class TestAssistant {
         builder.setSimpleLineBreaking(isSimpleLineBreaking(testDoc));
         builder.setSkipPagePositionOnlyAllowed(isSkipPagePositionOnlyAllowed(testDoc));
         builder.setLegacySkipPagePositionOnly(isLegacySkipPagePositionOnly(testDoc));
+        builder.setLegacyLastPageChangeIPD(isLegacyLastPageChangeIPD(testDoc));
         return builder.build();
     }
 
@@ -189,6 +190,15 @@ public class TestAssistant {
         }
     }
 
+    private boolean isLegacyLastPageChangeIPD(Document testDoc) {
+        try {
+            String s = eval(testDoc, "/testcase/cfg/legacy-last-page-change-ipd");
+            return "true".equalsIgnoreCase(s);
+        } catch (XPathExpressionException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     /**
      * Loads a test case into a DOM document.
      * @param testFile the test file