don't prepare URLs for oddball schemes

requests/models.py

@@ -327,6 +327,11 @@ class PreparedRequest(RequestEncodingMixin, RequestHooksMixin):
             raise MissingSchema("Invalid URL {0!r}: No schema supplied. "
                                 "Perhaps you meant http://{0}?".format(url))
 
+        # Don't do any URL preparation for oddball schemes
+        if scheme.lower() not in ('http', 'https'):
+            self.url = url
+            return
+
         if not host:
             raise InvalidURL("Invalid URL %r: No host supplied" % url)
 

requests/packages/urllib3/util.py

@@ -365,6 +365,8 @@ def parse_url(url):
     # Scheme
     if '://' in url:
         scheme, url = url.split('://', 1)
+    elif ':' in url:
+        scheme, url = url.split(':', 1)
 
     # Find the earliest Authority Terminator
     # (http://tools.ietf.org/html/rfc3986#section-3.2)

test_requests.py

@@ -678,6 +678,14 @@ class RequestsTestCase(unittest.TestCase):
 
         assert p.headers['Content-Length'] == length
 
+    def test_oddball_schemes_dont_check_URLs(self):
+        r1 = requests.Request('GET', 'data:image/gif;base64,R0lGODlhAQABAHAAACH5BAUAAAAALAAAAAABAAEAAAICRAEAOw==')
+        r1.prepare()
+        r2 = requests.Request('GET', 'file:///etc/passwd')
+        r2.prepare()
+        r3 = requests.Request('GET', 'magnet:?xt=urn:btih:be08f00302bc2d1d3cfa3af02024fa647a271431')
+        r3.prepare()
+
 class TestContentEncodingDetection(unittest.TestCase):
 
     def test_none(self):