Index: src/test/org/apache/lucene/index/TestTerm.java
===================================================================
--- src/test/org/apache/lucene/index/TestTerm.java	(revision 0)
+++ src/test/org/apache/lucene/index/TestTerm.java	(revision 0)
@@ -0,0 +1,19 @@
+package org.apache.lucene.index;
+
+import junit.framework.TestCase;
+
+public class TestTerm extends TestCase {
+
+  public void testEquals() {
+    final Term base = new Term("same", "same");
+    final Term same = new Term("same", "same");
+    final Term differentField = new Term("different", "same");
+    final Term differentText = new Term("same", "different");
+    final String differentType = "AString";
+    assertEquals(base, base);
+    assertEquals(base, same);
+    assertFalse(base.equals(differentField));
+    assertFalse(base.equals(differentText));
+    assertFalse(base.equals(differentType));
+  }
+}
Index: src/java/org/apache/lucene/index/Term.java
===================================================================
--- src/java/org/apache/lucene/index/Term.java	(revision 515924)
+++ src/java/org/apache/lucene/index/Term.java	(working copy)
@@ -63,8 +63,12 @@
   /** Compares two terms, returning true iff they have the same
       field and text. */
   public final boolean equals(Object o) {
+    if (o == this)
+      return true;
     if (o == null)
       return false;
+    if (!(o instanceof Term))
+      return false;
     Term other = (Term)o;
     return field == other.field && text.equals(other.text);
   }