Fixed issue11082 - Reject str for POST data with a TypeError. Document the need to explicitly encode to bytes when using urlencode.

2 files changed, 11 insertions, 4 deletions

diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index 17323d5..1433670 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -794,6 +794,10 @@ class HandlerTests(unittest.TestCase):
         http.raise_on_endheaders = True
         self.assertRaises(urllib.error.URLError, h.do_open, http, req)
 
+        # Check for TypeError on POST data which is str.
+        req = Request("http://example.com/","badpost")
+        self.assertRaises(TypeError, h.do_request_, req)
+
         # check adding of standard headers
         o.addheaders = [("Spam", "eggs")]
         for data in b"", None:  # POST, GET
@@ -837,10 +841,11 @@ class HandlerTests(unittest.TestCase):
             else:
                 newreq = h.do_request_(req)
 
-        # A file object
+        # A file object.
+        # Test only Content-Length attribute of request.
 
-        file_obj = io.StringIO()
-        file_obj.write("Something\nSomething\nSomething\n")
+        file_obj = io.BytesIO()
+        file_obj.write(b"Something\nSomething\nSomething\n")
 
         for headers in {}, {"Content-Length": 30}:
             req = Request("http://example.com/", file_obj, headers)
@@ -863,7 +868,6 @@ class HandlerTests(unittest.TestCase):
             newreq = h.do_request_(req)
             self.assertEqual(int(newreq.get_header('Content-length')),16)
 
-
     def test_http_doubleslash(self):
         # Checks the presence of any unnecessary double slash in url does not
         # break anything. Previously, a double slash directly after the host
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index a188393..dfdbdec 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1048,6 +1048,9 @@ class AbstractHTTPHandler(BaseHandler):
 
         if request.data is not None:  # POST
             data = request.data
+            if isinstance(data, str):
+                raise TypeError("POST data should be bytes"
+                        " or an iterable of bytes. It cannot be str.")
             if not request.has_header('Content-type'):
                 request.add_unredirected_header(
                     'Content-type',