Index: contrib/queries/src/test/org/apache/lucene/search/trie/TestTrieRangeQuery.java
===================================================================
--- contrib/queries/src/test/org/apache/lucene/search/trie/TestTrieRangeQuery.java	(revision 740444)
+++ contrib/queries/src/test/org/apache/lucene/search/trie/TestTrieRangeQuery.java	(working copy)
@@ -36,11 +36,10 @@
 {
   private static final long distance=66666;
   
-  private static Random rnd=new Random();
-  private static RAMDirectory directory;
-  private static IndexSearcher searcher;
+  private static final RAMDirectory directory;
+  private static final IndexSearcher searcher;
   static {
-    try {
+    try {    
       directory = new RAMDirectory();
       IndexWriter writer = new IndexWriter(directory, new WhitespaceAnalyzer(),
       true, MaxFieldLength.UNLIMITED);
@@ -136,6 +135,7 @@
   }
   
   private void testRandomTrieAndClassicRangeQuery(final TrieUtils variant) throws Exception {
+    final Random rnd=newRandom();
     String field="field"+variant.TRIE_BITS;
     // 50 random tests, the tests may also return 0 results, if min>max, but this is ok
     for (int i=0; i<50; i++) {
@@ -185,6 +185,7 @@
   }
   
   private void testRangeSplit(final TrieUtils variant) throws Exception {
+    final Random rnd=newRandom();
     String field="ascfield"+variant.TRIE_BITS;
     // 50 random tests
     for (int i=0; i<50; i++) {
@@ -225,6 +226,7 @@
   }
   
   private void testSorting(final TrieUtils variant) throws Exception {
+    final Random rnd=newRandom();
     String field="field"+variant.TRIE_BITS;
     // 10 random tests, the index order is ascending,
     // so using a reverse sort field should retun descending documents
Index: src/test/org/apache/lucene/util/LuceneTestCase.java
===================================================================
--- src/test/org/apache/lucene/util/LuceneTestCase.java	(revision 740441)
+++ src/test/org/apache/lucene/util/LuceneTestCase.java	(working copy)
@@ -20,6 +20,7 @@
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.index.ConcurrentMergeScheduler;
 import junit.framework.TestCase;
+import java.util.Random;
 
 /** Base class for all Lucene unit tests.  Currently the
  *  only added functionality over JUnit's TestCase is
@@ -54,4 +55,41 @@
       fail("ConcurrentMergeScheduler hit unhandled exceptions");
     }
   }
+  
+  /**
+   * Returns a {@link Random} instance for generating random numbers during the test.
+   * The random seed is logged during test execution and printed to System.out on any failure
+   * for reproducing the test using {@link #getRandom(long)} with the recorded seed
+   *.
+   */
+  public Random newRandom() {
+    return newRandom(seedRnd.nextLong());
+  }
+  
+  /**
+   * Returns a {@link Random} instance for generating random numbers during the test.
+   * If an error occurs in the test that is not reproducible, you can use this method to
+   * initialize the number generator with the seed that was printed out during the failing test.
+   */
+  public Random newRandom(long seed) {
+    this.seed=new Long(seed);
+    return new Random(seed);
+  }
+  
+  protected void runTest() throws Throwable {
+    try {
+      super.runTest();
+    } catch (Throwable e) {
+      if (seed!=null) {
+        System.out.println("Random seed of test '"+getName()+"' was: "+seed);
+      }
+      throw e;
+    }
+  }
+  
+  // recorded seed
+  protected Long seed=null;
+  
+  // static members
+  private static final Random seedRnd=new Random();
 }