4 files changed, 98 insertions, 15 deletions
diff --git a/src/mailman/rest/configuration.py b/src/mailman/rest/configuration.py
index 95bcf32db..05a062b02 100644
--- a/src/mailman/rest/configuration.py
+++ b/src/mailman/rest/configuration.py
@@ -31,7 +31,7 @@ from restish import http, resource
 from mailman.config import config
 from mailman.interfaces.autorespond import ResponseAction
 from mailman.interfaces.mailinglist import IAcceptableAliasSet
-from mailman.rest.helpers import etag
+from mailman.rest.helpers import PATCH, etag
 from mailman.rest.validator import Validator, enum_validator
 
 
@@ -232,18 +232,29 @@ class ListConfiguration(resource.Resource):
             resource[attribute] = value
         return http.ok([], etag(resource))
 
+    # XXX 2010-09-01 barry: Refactor {put,patch}_configuration() for common
+    # code paths.
+
+    def _set_writable_attributes(self, validator, request):
+        """Common code for setting all attributes given in the request.
+
+        Returns an HTTP 400 when a request tries to write to a read-only
+        attribute.
+        """
+        converted = validator(request)
+        for key, value in converted.items():
+            ATTRIBUTES[key].put(self._mlist, key, value)
+
     @resource.PUT()
     def put_configuration(self, request):
         """Set a mailing list configuration."""
         attribute = self._attribute
         if attribute is None:
-            # Set all writable attributes.
+            validator = Validator(**VALIDATORS)
             try:
-                converted = Validator(**VALIDATORS)(request)
+                self._set_writable_attributes(validator, request)
             except ValueError as error:
                 return http.bad_request([], str(error))
-            for key, value in converted.items():
-                ATTRIBUTES[key].put(self._mlist, key, value)
         elif attribute not in ATTRIBUTES:
             return http.bad_request(
                 [], b'Unknown attribute: {0}'.format(attribute))
@@ -253,9 +264,28 @@ class ListConfiguration(resource.Resource):
         else:
             validator = Validator(**{attribute: VALIDATORS[attribute]})
             try:
-                values = validator(request)
+                self._set_writable_attributes(validator, request)
             except ValueError as error:
                 return http.bad_request([], str(error))
-            ATTRIBUTES[attribute].put(
-                self._mlist, attribute, values[attribute])
+        return http.ok([], '')
+
+    @PATCH()
+    def patch_configuration(self, request):
+        """Patch the configuration (i.e. partial update)."""
+        # Validate only the partial subset of attributes given in the request.
+        validationators = {}
+        for attribute in request.PATCH:
+            if attribute not in ATTRIBUTES:
+                return http.bad_request(
+                    [], b'Unknown attribute: {0}'.format(attribute))
+            elif ATTRIBUTES[attribute].decoder is None:
+                return http.bad_request(
+                    [], b'Read-only attribute: {0}'.format(attribute))
+            else:
+                validationators[attribute] = VALIDATORS[attribute]
+        validator = Validator(**validationators)
+        try:
+            self._set_writable_attributes(validator, request)
+        except ValueError as error:
+            return http.bad_request([], str(error))
         return http.ok([], '')
diff --git a/src/mailman/rest/docs/configuration.txt b/src/mailman/rest/docs/configuration.txt
index 1ad374d32..63f87fde1 100644
--- a/src/mailman/rest/docs/configuration.txt
+++ b/src/mailman/rest/docs/configuration.txt
@@ -303,15 +303,20 @@ Changing a partial configuration
 
 Using PATCH, you can change just one attribute.
 
-XXX WebOb does not currently support PATCH, so neither does restish.
-
-#    >>> dump_json('http://localhost:8001/3.0/lists/'
-#    ...           'test-one@example.com/config',
-#    ...           dict(real_name='My List'),
-#    ...           'PATCH')
+    >>> dump_json('http://localhost:8001/3.0/lists/'
+    ...           'test-one@example.com/config',
+    ...           dict(real_name='My List'),
+    ...           'PATCH')
+    content-length: 0
+    date: ...
+    server: ...
+    status: 200
 
 These values are changed permanently.
 
+    >>> print mlist.real_name
+    My List
+
 
 Sub-resources
 =============
diff --git a/src/mailman/rest/helpers.py b/src/mailman/rest/helpers.py
index 3117ed47e..dc67a699b 100644
--- a/src/mailman/rest/helpers.py
+++ b/src/mailman/rest/helpers.py
@@ -22,6 +22,7 @@ from __future__ import absolute_import, unicode_literals
 __metaclass__ = type
 __all__ = [
     'ContainerMixin',
+    'PATCH',
     'etag',
     'no_content',
     'path_to',
@@ -29,13 +30,17 @@ __all__ = [
     ]
 
 
+import cgi
 import json
 import hashlib
 
+from cStringIO import StringIO
 from datetime import datetime, timedelta
 from flufl.enum import Enum
 from lazr.config import as_boolean
 from restish.http import Response
+from restish.resource import MethodDecorator
+from webob.multidict import MultiDict
 
 from mailman.config import config
 
@@ -163,3 +168,41 @@ def restish_matcher(function):
 def no_content():
     """204 No Content."""
     return Response('204 No Content', [], None)
+
+
+# These two classes implement an ugly, dirty hack to work around the fact that
+# neither WebOb nor really the stdlib cgi module support non-standard HTTP
+# verbs such as PATCH.  Note that restish handles it just fine in the sense
+# that the right method gets called, but without the following kludge, the
+# body of the request will never get decoded, so the method won't see any
+# data.
+#
+# Stuffing the MultiDict on request.PATCH is pretty ugly, but it mirrors
+# WebOb's use of request.POST and request.PUT for those standard verbs.
+# Besides, WebOb refuses to allow us to set request.POST.  This does make
+# validators.py a bit more complicated. :(
+
+class PATCHWrapper:
+    """Hack to decode the request body for PATCH."""
+    def __init__(self, func):
+        self.func = func
+
+    def __call__(self, resource, request):
+        # We can't use request.body_file because that's a socket that's
+        # already had its data read off of.  IOW, if we use that directly,
+        # we'll block here.
+        field_storage = cgi.FieldStorage(
+            fp=StringIO(request.body),
+            # Yes, lie about the method so cgi will do the right thing.
+            environ=dict(REQUEST_METHOD='POST'),
+            keep_blank_values=True)
+        request.PATCH = MultiDict.from_fieldstorage(field_storage)
+        return self.func(resource, request)
+
+
+class PATCH(MethodDecorator):
+    method = 'PATCH'
+
+    def __call__(self, func):
+        really_wrapped_func = PATCHWrapper(func)
+        return super(PATCH, self).__call__(really_wrapped_func)
diff --git a/src/mailman/rest/validator.py b/src/mailman/rest/validator.py
index e9bcf4729..cf51cee75 100644
--- a/src/mailman/rest/validator.py
+++ b/src/mailman/rest/validator.py
@@ -61,7 +61,12 @@ class Validator:
         # in the pre-converted dictionary.  All keys which show up more than
         # once get a list value.
         missing = object()
-        for key, new_value in request.POST.items():
+        # This is a gross hack to allow PATCH.  See helpers.py for details.
+        try:
+            items = request.PATCH.items()
+        except AttributeError:
+            items = request.POST.items()
+        for key, new_value in items:
             old_value = form_data.get(key, missing)
             if old_value is missing:
                 form_data[key] = new_value