From 33bf336cd48bbd8a656e41e7c8a52e45a89a97b9 Mon Sep 17 00:00:00 2001
From: Robert Muir <rmuir@apache.org>
Date: Tue, 1 Jul 2014 16:52:20 +0000
Subject: [PATCH] remove dead states after union(), just like intersection()
 and complement() do

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1607139 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/lucene/util/automaton/Operations.java     | 2 +-
 .../org/apache/lucene/util/automaton/TestOperations.java | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lucene/core/src/java/org/apache/lucene/util/automaton/Operations.java b/lucene/core/src/java/org/apache/lucene/util/automaton/Operations.java
index 24f85f8a8d6..02e84c220b5 100644
--- a/lucene/core/src/java/org/apache/lucene/util/automaton/Operations.java
+++ b/lucene/core/src/java/org/apache/lucene/util/automaton/Operations.java
@@ -505,7 +505,7 @@ final public class Operations {
 
     result.finishState();
 
-    return result;
+    return removeDeadStates(result);
   }
 
   // Simple custom ArrayList<Transition>
diff --git a/lucene/core/src/test/org/apache/lucene/util/automaton/TestOperations.java b/lucene/core/src/test/org/apache/lucene/util/automaton/TestOperations.java
index e4f228033f0..7b2db1f0080 100644
--- a/lucene/core/src/test/org/apache/lucene/util/automaton/TestOperations.java
+++ b/lucene/core/src/test/org/apache/lucene/util/automaton/TestOperations.java
@@ -34,7 +34,14 @@ public class TestOperations extends LuceneTestCase {
     Collections.sort(strings);
     Automaton union = Automata.makeStringUnion(strings);
     assertTrue(union.isDeterministic());
-    assertTrue(Operations.sameLanguage(union, naiveUnion(strings)));
+    assertFalse(Operations.hasDeadStatesFromInitial(union));
+    
+    Automaton naiveUnion = naiveUnion(strings);
+    assertTrue(naiveUnion.isDeterministic());
+    assertFalse(Operations.hasDeadStatesFromInitial(naiveUnion));
+
+    
+    assertTrue(Operations.sameLanguage(union, naiveUnion));
   }
 
   private static Automaton naiveUnion(List<BytesRef> strings) {