[1.3.X] Fixed #16201 -- Ensure that requests with Content-Length=0 don't break the multipart parser. Thanks to albsen for the report and patch

Backport of r16353 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.3.X@16676 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 27 insertions, 1 deletions

diff --git a/django/http/multipartparser.py b/django/http/multipartparser.py
index e45d5d1035..e3a03ff897 100644
--- a/django/http/multipartparser.py
+++ b/django/http/multipartparser.py
@@ -75,7 +75,7 @@ class MultiPartParser(object):
             # For now set it to 0; we'll try again later on down.
             content_length = 0
 
-        if content_length <= 0:
+        if content_length < 0:
             # This means we shouldn't continue...raise an error.
             raise MultiPartParserError("Invalid content length: %r" % content_length)
 
@@ -105,6 +105,11 @@ class MultiPartParser(object):
         encoding = self._encoding
         handlers = self._upload_handlers
 
+        # HTTP spec says that Content-Length >= 0 is valid
+        # handling content-length == 0 before continuing
+        if self._content_length == 0:
+            return QueryDict(MultiValueDict(), encoding=self._encoding), MultiValueDict()
+
         limited_input_data = LimitBytes(self._input_data, self._content_length)
 
         # See if the handler will want to take care of the parsing.
diff --git a/tests/regressiontests/requests/tests.py b/tests/regressiontests/requests/tests.py
index b68201494b..154c1fa07d 100644
--- a/tests/regressiontests/requests/tests.py
+++ b/tests/regressiontests/requests/tests.py
@@ -200,6 +200,27 @@ class RequestsTests(unittest.TestCase):
         self.assertEqual(request.POST, {u'name': [u'value']})
         self.assertRaises(Exception, lambda: request.raw_post_data)
 
+    def test_POST_multipart_with_content_length_zero(self):
+        """
+        Multipart POST requests with Content-Length >= 0 are valid and need to be handled.
+        """
+        # According to:
+        # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.13
+        # Every request.POST with Content-Length >= 0 is a valid request,
+        # this test ensures that we handle Content-Length == 0.
+        payload = "\r\n".join([
+                '--boundary',
+                'Content-Disposition: form-data; name="name"',
+                '',
+                'value',
+                '--boundary--'
+                ''])
+        request = WSGIRequest({'REQUEST_METHOD': 'POST',
+                               'CONTENT_TYPE': 'multipart/form-data; boundary=boundary',
+                               'CONTENT_LENGTH': 0,
+                               'wsgi.input': StringIO(payload)})
+        self.assertEqual(request.POST, {})
+
     def test_read_by_lines(self):
         request = WSGIRequest({'REQUEST_METHOD': 'POST', 'wsgi.input': StringIO('name=value')})
         self.assertEqual(list(request), ['name=value'])