Index: src/org/python/modules/time/Time.java
===================================================================
--- src/org/python/modules/time/Time.java	(revision 7168)
+++ src/org/python/modules/time/Time.java	(working copy)
@@ -759,6 +759,10 @@
         boolean directive = false;
         boolean inQuote = false;
 
+        if (format.length() == 0) {
+            return null;
+        }
+
         for (int i = 0; i < format.length(); i++) {
             char charAt = format.charAt(i);
 
Index: Lib/test/test_time.py
===================================================================
--- Lib/test/test_time.py	(revision 7168)
+++ Lib/test/test_time.py	(working copy)
@@ -120,6 +120,12 @@
             except ValueError:
                 self.fail('conversion specifier: %r failed.' % format)
 
+    def test_strptime_empty(self):
+        try:
+            time.strptime('', '')
+        except ValueError:
+            self.fail('strptime failed on empty args.')
+
     def test_asctime(self):
         time.asctime(time.gmtime(self.t))
         self.assertRaises(TypeError, time.asctime, 0)