Fix SF #1117398, cookielib LWPCookieJar and MozillaCookieJar exceptions

cookielib.LWPCookieJar and .MozillaCookieJar are documented to raise
cookielib.LoadError on attempt to load an invalid cookies file, but
raise IOError instead.  Compromise by having LoadError subclass IOError.

Lib/_LWPCookieJar.py

@@ -12,8 +12,8 @@ libwww-perl, I hope.
 """
 
 import time, re, logging
-from cookielib import (reraise_unmasked_exceptions, FileCookieJar, Cookie,
-     MISSING_FILENAME_TEXT, join_header_words, split_header_words,
+from cookielib import (reraise_unmasked_exceptions, FileCookieJar, LoadError,
+     Cookie, MISSING_FILENAME_TEXT, join_header_words, split_header_words,
      iso2time, time2isoz)
 
 def lwp_cookie_str(cookie):
@@ -93,7 +93,7 @@ class LWPCookieJar(FileCookieJar):
         magic = f.readline()
         if not re.search(self.magic_re, magic):
             msg = "%s does not seem to contain cookies" % filename
-            raise IOError(msg)
+            raise LoadError(msg)
 
         now = time.time()
 
@@ -161,4 +161,4 @@ class LWPCookieJar(FileCookieJar):
                     self.set_cookie(c)
         except:
             reraise_unmasked_exceptions((IOError,))
-            raise IOError("invalid Set-Cookie3 format file %s" % filename)
+            raise LoadError("invalid Set-Cookie3 format file %s" % filename)

Lib/_MozillaCookieJar.py

@@ -2,8 +2,8 @@
 
 import re, time, logging
 
-from cookielib import (reraise_unmasked_exceptions, FileCookieJar, Cookie,
-     MISSING_FILENAME_TEXT)
+from cookielib import (reraise_unmasked_exceptions, FileCookieJar, LoadError,
+     Cookie, MISSING_FILENAME_TEXT)
 
 class MozillaCookieJar(FileCookieJar):
     """
@@ -50,7 +50,7 @@ class MozillaCookieJar(FileCookieJar):
         magic = f.readline()
         if not re.search(self.magic_re, magic):
             f.close()
-            raise IOError(
+            raise LoadError(
                 "%s does not look like a Netscape format cookies file" %
                 filename)
 
@@ -106,8 +106,8 @@ class MozillaCookieJar(FileCookieJar):
 
         except:
             reraise_unmasked_exceptions((IOError,))
-            raise IOError("invalid Netscape format file %s: %s" %
-                          (filename, line))
+            raise LoadError("invalid Netscape format file %s: %s" %
+                            (filename, line))
 
     def save(self, filename=None, ignore_discard=False, ignore_expires=False):
         if filename is None:

Lib/cookielib.py

@@ -1682,7 +1682,8 @@ class CookieJar:
         return "<%s[%s]>" % (self.__class__, ", ".join(r))
 
 
-class LoadError(Exception): pass
+# derives from IOError for backwards-compatibility with Python 2.4.0
+class LoadError(IOError): pass
 
 class FileCookieJar(CookieJar):
     """CookieJar that can be loaded from and saved to a file."""

Lib/test/test_cookielib.py

@@ -248,6 +248,31 @@ class FileCookieJarTests(TestCase):
             except OSError: pass
         self.assertEqual(c._cookies["www.acme.com"]["/"]["boo"].value, None)
 
+    def test_bad_magic(self):
+        from cookielib import LWPCookieJar, MozillaCookieJar, LoadError
+        # IOErrors (eg. file doesn't exist) are allowed to propagate
+        filename = test_support.TESTFN
+        for cookiejar_class in LWPCookieJar, MozillaCookieJar:
+            c = cookiejar_class()
+            try:
+                c.load(filename="for this test to work, a file with this "
+                                "filename should not exist")
+            except IOError, exc:
+                # exactly IOError, not LoadError
+                self.assertEqual(exc.__class__, IOError)
+            else:
+                self.fail("expected IOError for invalid filename")
+        # Invalid contents of cookies file (eg. bad magic string)
+        # causes a LoadError.
+        try:
+            f = open(filename, "w")
+            f.write("oops\n")
+            for cookiejar_class in LWPCookieJar, MozillaCookieJar:
+                c = cookiejar_class()
+                self.assertRaises(LoadError, c.load, filename)
+        finally:
+            try: os.unlink(filename)
+            except OSError: pass
 
 class CookieTests(TestCase):
     # XXX