Index: lucene/suggest/src/test/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggesterTest.java
===================================================================
--- lucene/suggest/src/test/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggesterTest.java	(revision 1400186)
+++ lucene/suggest/src/test/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggesterTest.java	(working copy)
@@ -803,4 +803,69 @@
 
     List<LookupResult> results = suggester.lookup("a", false, 4);
   }
+
+  public void testExactFirstMissingResult() throws Exception {
+
+    Analyzer a = new MockAnalyzer(random());
+
+    AnalyzingSuggester suggester = new AnalyzingSuggester(a, a, AnalyzingSuggester.EXACT_FIRST, 256, -1);
+
+    suggester.build(new TermFreqArrayIterator(new TermFreq[] {
+          new TermFreq("a", 5),
+          new TermFreq("a b", 3),
+          new TermFreq("a c", 4),
+        }));
+
+    // nocommit make this false and confirm test still
+    // failed before:
+    List<LookupResult> results = suggester.lookup("a", true, 3);
+    assertEquals(3, results.size());
+    assertEquals("a", results.get(0).key);
+    assertEquals(5, results.get(0).value);
+    assertEquals("a c", results.get(1).key);
+    assertEquals(4, results.get(1).value);
+    assertEquals("a b", results.get(2).key);
+    assertEquals(3, results.get(2).value);
+  }
+
+  public void testDupSurfaceFormsMissingResults() throws Exception {
+    Analyzer a = new Analyzer() {
+      @Override
+      protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
+        Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.SIMPLE, true);
+        
+        return new TokenStreamComponents(tokenizer) {
+
+          int count;
+
+          @Override
+          public TokenStream getTokenStream() {
+            return new CannedTokenStream(new Token[] {
+                token("hairy", 1, 1),
+                token("smelly", 0, 1),
+                token("dog", 1, 1),
+              });
+          }
+         
+          @Override
+          protected void setReader(final Reader reader) throws IOException {
+          }
+        };
+      }
+    };
+
+    AnalyzingSuggester suggester = new AnalyzingSuggester(a, a, 0, 256, -1);
+
+    suggester.build(new TermFreqArrayIterator(new TermFreq[] {
+          new TermFreq("hambone", 6),
+          new TermFreq("nellie", 5),
+        }));
+
+    List<LookupResult> results = suggester.lookup("nellie", false, 2);
+    assertEquals(2, results.size());
+    assertEquals("hambone", results.get(0).key);
+    assertEquals(6, results.get(0).value);
+    assertEquals("nellie", results.get(1).key);
+    assertEquals(5, results.get(1).value);
+  }
 }
Index: lucene/suggest/src/java/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggester.java
===================================================================
--- lucene/suggest/src/java/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggester.java	(revision 1400186)
+++ lucene/suggest/src/java/org/apache/lucene/search/suggest/analyzing/AnalyzingSuggester.java	(working copy)
@@ -591,16 +591,18 @@
 
       Util.TopNSearcher<Pair<Long,BytesRef>> searcher;
       searcher = new Util.TopNSearcher<Pair<Long,BytesRef>>(fst,
-                                                            num - results.size(),
+                                                            num,
                                                             weightComparator) {
         private final Set<BytesRef> seen = new HashSet<BytesRef>();
 
         @Override
         protected boolean acceptResult(IntsRef input, Pair<Long,BytesRef> output) {
-          
+
+          //System.out.println("ACCEPT? path=" + input);
           // Dedup: when the input analyzes to a graph we
           // can get duplicate surface forms:
           if (seen.contains(output.output2)) {
+            //System.out.println("SKIP: dup");
             return false;
           }
           seen.add(output.output2);
@@ -630,6 +632,12 @@
         LookupResult result = new LookupResult(spare.toString(), decodeWeight(completion.output.output1));
         //System.out.println("    result=" + result);
         results.add(result);
+
+        if (results.size() == num) {
+          // In the exactFirst=true case the search may
+          // produce one extra path
+          break;
+        }
       }
 
       return results;
Index: lucene/core/src/java/org/apache/lucene/util/fst/Util.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/util/fst/Util.java	(revision 1400186)
+++ lucene/core/src/java/org/apache/lucene/util/fst/Util.java	(working copy)
@@ -325,7 +325,7 @@
 
       if (queue.size() == topN+1) {
         queue.pollLast();
-      } 
+      }
     }
 
     /** Adds all leaving arcs, including 'finished' arc, if
@@ -390,8 +390,6 @@
           break;
         }
 
-        //System.out.println("  remove init path=" + path);
-
         if (path.arc.label == FST.END_LABEL) {
           //System.out.println("    empty string!  cost=" + path.cost);
           // Empty string!
@@ -400,10 +398,13 @@
           continue;
         }
 
+        // LUCENE-4481: TODO: re-enable this pruning if we can make this admissible:
+        /*
         if (results.size() == topN-1) {
           // Last path -- don't bother w/ queue anymore:
           queue = null;
         }
+        */
 
         //System.out.println("  path: " + path);