diff --git a/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestBugInSomething.java b/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestBugInSomething.java
new file mode 100644
index 00000000000..5cd5c65508b
--- /dev/null
+++ b/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestBugInSomething.java
@@ -0,0 +1,64 @@
+package org.apache.lucene.analysis.core;
+
+import java.io.Reader;
+
+import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.BaseTokenStreamTestCase;
+import org.apache.lucene.analysis.MockCharFilter;
+import org.apache.lucene.analysis.MockTokenFilter;
+import org.apache.lucene.analysis.MockTokenizer;
+import org.apache.lucene.analysis.TokenFilter;
+import org.apache.lucene.analysis.Tokenizer;
+import org.apache.lucene.analysis.charfilter.MappingCharFilter;
+import org.apache.lucene.analysis.charfilter.NormalizeCharMap;
+import org.apache.lucene.analysis.commongrams.CommonGramsFilter;
+import org.apache.lucene.analysis.util.CharArraySet;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+public class TestBugInSomething extends BaseTokenStreamTestCase {
+  public void test() throws Exception {
+    final CharArraySet cas = new CharArraySet(TEST_VERSION_CURRENT, 3, false);
+    cas.add("jjp");
+    cas.add("wlmwoknt");
+    cas.add("tcgyreo");
+    
+    final NormalizeCharMap map = new NormalizeCharMap();
+    map.add("mtqlpi", "");
+    map.add("mwoknt", "jjp");
+    map.add("tcgyreo", "zpfpajyws");
+    map.add("", "eethksv");
+    
+    Analyzer a = new Analyzer() {
+      @Override
+      protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
+        Tokenizer t = new MockTokenizer(new TestRandomChains.CheckThatYouDidntReadAnythingReaderWrapper(reader), MockTokenFilter.ENGLISH_STOPSET, false, -65);
+        TokenFilter f = new CommonGramsFilter(TEST_VERSION_CURRENT, t, cas);
+        return new TokenStreamComponents(t, f);
+      }
+
+      @Override
+      protected Reader initReader(Reader reader) {
+        reader = new MockCharFilter(reader, 0);
+        reader = new MappingCharFilter(map, reader);
+        return reader;
+      }
+    };
+    checkAnalysisConsistency(random(), a, false, "wmgddzunizdomqyj");
+  }
+}
diff --git a/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestRandomChains.java b/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestRandomChains.java
index e1804868c95..fdd5aadb123 100644
--- a/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestRandomChains.java
+++ b/modules/analysis/common/src/test/org/apache/lucene/analysis/core/TestRandomChains.java
@@ -756,44 +756,77 @@ public class TestRandomChains extends BaseTokenStreamTestCase {
     }
   }
   
-  static final class CheckThatYouDidntReadAnythingReaderWrapper extends CharFilter {
-    boolean readSomething = false;
+  // wants charfilter to be a filterreader...
+  // do *NOT* refactor me to be a charfilter: LUCENE-3990
+  static class CheckThatYouDidntReadAnythingReaderWrapper extends CharStream {
+    boolean readSomething;
+    CharStream in;
     
     CheckThatYouDidntReadAnythingReaderWrapper(Reader in) {
-      super(CharReader.get(in));
+      this.in = CharReader.get(in);
+    }
+    
+    @Override
+    public int correctOffset(int currentOff) {
+      return in.correctOffset(currentOff);
+    }
+
+    @Override
+    public void close() throws IOException {
+      in.close();
     }
 
     @Override
     public int read(char[] cbuf, int off, int len) throws IOException {
       readSomething = true;
-      return super.read(cbuf, off, len);
+      return in.read(cbuf, off, len);
     }
 
     @Override
     public int read() throws IOException {
       readSomething = true;
-      return super.read();
+      return in.read();
     }
 
     @Override
     public int read(CharBuffer target) throws IOException {
       readSomething = true;
-      return super.read(target);
+      return in.read(target);
+    }
+
+    @Override
+    public void mark(int readAheadLimit) throws IOException {
+      in.mark(readAheadLimit);
+    }
+
+    @Override
+    public boolean markSupported() {
+      return in.markSupported();
     }
 
     @Override
     public int read(char[] cbuf) throws IOException {
       readSomething = true;
-      return super.read(cbuf);
+      return in.read(cbuf);
+    }
+
+    @Override
+    public boolean ready() throws IOException {
+      return in.ready();
+    }
+
+    @Override
+    public void reset() throws IOException {
+      in.reset();
     }
 
     @Override
     public long skip(long n) throws IOException {
       readSomething = true;
-      return super.skip(n);
+      return in.skip(n);
     }
   }
-  
+
   static class TokenizerSpec {
     Tokenizer tokenizer;
     String toString;