Index: src/test/org/apache/lucene/search/spans/TestSpans.java
===================================================================
--- src/test/org/apache/lucene/search/spans/TestSpans.java	(revision 509370)
+++ src/test/org/apache/lucene/search/spans/TestSpans.java	(working copy)
@@ -210,6 +210,10 @@
   public void testSpanOrEmpty() throws Exception {
     Spans spans = orSpans(new String[0]);
     assertFalse("empty next", spans.next());
+
+    SpanOrQuery a = new SpanOrQuery( new SpanQuery[0] );
+    SpanOrQuery b = new SpanOrQuery( new SpanQuery[0] );
+    assertTrue("empty should equal", a.equals(b));
   }
 
   public void testSpanOrSingle() throws Exception {
Index: src/java/org/apache/lucene/search/spans/SpanOrQuery.java
===================================================================
--- src/java/org/apache/lucene/search/spans/SpanOrQuery.java	(revision 509370)
+++ src/java/org/apache/lucene/search/spans/SpanOrQuery.java	(working copy)
@@ -121,7 +121,7 @@
     final SpanOrQuery that = (SpanOrQuery) o;
 
     if (!clauses.equals(that.clauses)) return false;
-    if (!field.equals(that.field)) return false;
+    if (!clauses.isEmpty() && !field.equals(that.field)) return false;
 
     return getBoost() == that.getBoost();
   }