Index: Lib/gzip.py
===================================================================
--- Lib/gzip.py	(revision 77458)
+++ Lib/gzip.py	(working copy)
@@ -330,6 +330,15 @@
         elif isize != (self.size & 0xffffffffL):
             raise IOError, "Incorrect length of data produced"
 
+        # Gzip files can be padded with zeroes and still have archives.
+        # Consume all zero bytes and set the file position to the first
+        # non-zero byte. See http://www.gzip.org/#faq8
+        c = "\x00"
+        while c and c == "\x00":
+            c = self.fileobj.read(1)
+        if c:
+            self.fileobj.seek(-1, 1)
+
     @property
     def closed(self):
         return self.fileobj is None
Index: Lib/test/test_gzip.py
===================================================================
--- Lib/test/test_gzip.py	(revision 77458)
+++ Lib/test/test_gzip.py	(working copy)
@@ -252,6 +252,21 @@
         else:
             self.fail("1/0 didn't raise an exception")
 
+    def test_zero_padded_file(self):
+        with gzip.GzipFile(self.filename, "wb") as f:
+            f.write(data1 * 50)
+
+        # Pad the file with zeroes
+        with open(self.filename, "ab") as f:
+            f.write("\x00" * 50)
+
+        try:
+            with gzip.GzipFile(self.filename, "rb") as f:
+                d = f.read()
+                self.assertEqual(d, data1 * 50, "Incorrect data in file")
+        except IOError as err:
+            self.fail(err)
+
 def test_main(verbose=None):
     test_support.run_unittest(TestGzip)