Index: modules/analysis/common/src/test/org/apache/lucene/analysis/synonym/TestSynonymMapFilter.java
===================================================================
--- modules/analysis/common/src/test/org/apache/lucene/analysis/synonym/TestSynonymMapFilter.java	(revision 1157834)
+++ modules/analysis/common/src/test/org/apache/lucene/analysis/synonym/TestSynonymMapFilter.java	(working copy)
@@ -29,10 +29,12 @@
 
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.BaseTokenStreamTestCase;
+import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.analysis.MockTokenizer;
 import org.apache.lucene.analysis.Tokenizer;
 import org.apache.lucene.analysis.tokenattributes.*;
 import org.apache.lucene.analysis.util.ReusableAnalyzerBase;
+import org.apache.lucene.analysis.util.ReusableAnalyzerBase.TokenStreamComponents;
 import org.apache.lucene.util.CharsRef;
 import org.apache.lucene.util._TestUtil;
 
@@ -390,4 +392,32 @@
       checkRandomData(random, analyzer, 1000*RANDOM_MULTIPLIER);
     }
   }
+  
+  // LUCENE-3375
+  public void testVanishingTerms() throws Exception {
+    String testFile = 
+      "aaa => aaaa1 aaaa2 aaaa3\n" + 
+      "bbb => bbbb1 bbbb2\n";
+      
+    SolrSynonymParser parser = new SolrSynonymParser(true, true, new MockAnalyzer(random));
+    parser.add(new StringReader(testFile));
+    final SynonymMap map = parser.build();
+      
+    Analyzer analyzer = new ReusableAnalyzerBase() {
+      @Override
+      protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
+        Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.WHITESPACE, true);
+        return new TokenStreamComponents(tokenizer, new SynonymFilter(tokenizer, map, true));
+      }
+    };
+    
+    // where did my pot go?!
+    assertAnalyzesTo(analyzer, "xyzzy bbb pot of gold",
+      new String[] { "xyzzy", "bbbb1", "bbbb2", "pot", "of", "gold" });
+    
+    // this one nukes 'pot' and 'of'
+    // xyzzy aaa pot of gold -> xyzzy aaaa1 aaaa2 aaaa3 gold
+    assertAnalyzesTo(analyzer, "xyzzy aaa pot of gold",
+      new String[] { "xyzzy", "aaaa1", "aaaa2", "pot", "aaaa3", "of", "gold" });
+  }
 }