Index: Lib/zipfile.py
===================================================================
--- Lib/zipfile.py	(revision 84249)
+++ Lib/zipfile.py	(working copy)
@@ -238,6 +238,9 @@
     if start >= 0:
         # found the magic number; attempt to unpack and interpret
         recData = data[start:start+sizeEndCentDir]
+        if len(recData) != sizeEndCentDir:
+            # Zip file is corrupted.
+            return
         endrec = list(struct.unpack(structEndArchive, recData))
         comment = data[start+sizeEndCentDir:]
         # check that comment length is correct
Index: Lib/test/test_zipfile.py
===================================================================
--- Lib/test/test_zipfile.py	(revision 84249)
+++ Lib/test/test_zipfile.py	(working copy)
@@ -745,6 +745,21 @@
         fp.seek(0, 0)
         chk = zipfile.is_zipfile(fp)
         self.assertTrue(not chk)
+        
+    def test_damaged_zipfile(self):
+        """Check that zipfiles with missing bytes at the end raise BadZipfile."""
+        # - Create a valid zip file
+        with zipfile.ZipFile(TESTFN, mode="w") as zipf:
+            zipf.writestr("foo.txt", b"O, for a Muse of Fire!")
+            
+        # - Now create copies of it missing the last N bytes and make sure
+        #   a BadZipfile exception is raised when we try to open it
+        s = open(TESTFN, "rb").read()
+        for N in range(len(s) - 2):
+            f = open(TESTFN2, "wb")
+            f.write(s[:N])
+            f.close()
+            self.assertRaises(zipfile.BadZipfile, zipfile.ZipFile, TESTFN2)            
 
     def test_is_zip_valid_file(self):
         """Check that is_zipfile() correctly identifies zip files."""