3 files changed, 6 insertions, 28 deletions

diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index 33f886d6f..926bb19aa 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -175,6 +175,7 @@ REST
    3.0 except that UUIDs are represented as hex strings instead of 128-bit
    integers, since the latter are not compatible with all versions of
    JavaScript.  (Closes #121)
+ * REST clients must minimally support HTTP/1.1. (Closes #288)
  * The new template system is introduced for API 3.1.  See
    ``src/mailman/rest/docs/templates.rst`` for details.  (Closes #249)
  * When creating a user via REST using an address that already exists, but
diff --git a/src/mailman/rest/tests/test_basic.py b/src/mailman/rest/tests/test_basic.py
index fade3ed40..23db57f8e 100644
--- a/src/mailman/rest/tests/test_basic.py
+++ b/src/mailman/rest/tests/test_basic.py
@@ -48,8 +48,8 @@ class TestBasicREST(unittest.TestCase):
                          'A description with , to check stuff')
 
     def test_send_error(self):
-        # Test `AdminWebServiceWSGIRequestHandler` `send_error`.
-        # Return 400 for invalid url.
+        # GL#288 working around Python bug #28548.  The improperly encoded
+        # space in the URL breaks error reporting due to default HTTP/0.9.
         with self.assertRaises(HTTPError) as cm:
             call_api('http://localhost:9001/3.0/lists/test @example.com')
         self.assertEqual(cm.exception.code, 400)
diff --git a/src/mailman/rest/wsgiapp.py b/src/mailman/rest/wsgiapp.py
index e31a46223..3ba122c00 100644
--- a/src/mailman/rest/wsgiapp.py
+++ b/src/mailman/rest/wsgiapp.py
@@ -18,7 +18,6 @@
 """Basic WSGI Application object for REST server."""
 
 import re
-import time
 import logging
 
 from base64 import b64decode
@@ -64,8 +63,9 @@ class StderrLogger:
 
 
 class AdminWebServiceWSGIRequestHandler(WSGIRequestHandler):
-    """Handler class which logs output to the right place and prepend headers
-    to the error response."""
+    """Handler class which just logs output to the right place."""
+
+    default_request_version = 'HTTP/1.1'
 
     def log_message(self, format, *args):
         """See `BaseHTTPRequestHandler`."""
@@ -76,29 +76,6 @@ class AdminWebServiceWSGIRequestHandler(WSGIRequestHandler):
         # the log file.
         return StderrLogger()
 
-    def send_error(self, code, message=None, explain=None):
-        """See `BaseHTTPRequestHandler`."""
-        try:
-            shortmsg = self.responses[code][0]
-        except KeyError:
-            shortmsg = '???'
-        err_code = "{0} {1}".format(int(code), shortmsg)
-        header_dict = dict(
-            status="{0} {1}".format(self.request_version, err_code),
-            rsp_date=time.strftime("%a, %d %b %Y %H:%M:%S %Z", time.gmtime()),
-            server="{0} {1}".format(self.server_version, self.sys_version),
-            content_type=self.error_content_type)
-        # Prepare headers and prepend it to the error response body
-        error_headers = ("""\
-%(status)s
-Date: %(rsp_date)s
-Server: %(server)s
-content-type: %(content_type)s\n
-""" % header_dict)
-        self.error_message_format = error_headers + self.error_message_format
-        # Let parent method handle rest of the logic
-        super().send_error(code, message, explain)
-
 
 class Middleware:
     """Falcon middleware object for Mailman's REST API.