Remove usage of request.postpath

This is an undocumented variable in twisted, and relies on the servlet
being mounted in the right way.

This also breaks getting push rules on workers.

synapse/rest/client/v1/push_rule.py

@@ -31,7 +31,7 @@ from .base import ClientV1RestServlet, client_path_patterns
 
 
 class PushRuleRestServlet(ClientV1RestServlet):
-    PATTERNS = client_path_patterns("/pushrules/.*$")
+    PATTERNS = client_path_patterns("/(?P<path>pushrules/.*)$")
     SLIGHTLY_PEDANTIC_TRAILING_SLASH_ERROR = (
         "Unrecognised request: You probably wanted a trailing slash")
 
@@ -42,11 +42,11 @@ class PushRuleRestServlet(ClientV1RestServlet):
         self._is_worker = hs.config.worker_app is not None
 
     @defer.inlineCallbacks
-    def on_PUT(self, request):
+    def on_PUT(self, request, path):
         if self._is_worker:
             raise Exception("Cannot handle PUT /push_rules on worker")
 
-        spec = _rule_spec_from_path([x.decode('utf8') for x in request.postpath])
+        spec = _rule_spec_from_path([x for x in path.split("/")])
         try:
             priority_class = _priority_class_from_spec(spec)
         except InvalidRuleException as e:
@@ -106,11 +106,11 @@ class PushRuleRestServlet(ClientV1RestServlet):
         defer.returnValue((200, {}))
 
     @defer.inlineCallbacks
-    def on_DELETE(self, request):
+    def on_DELETE(self, request, path):
         if self._is_worker:
             raise Exception("Cannot handle DELETE /push_rules on worker")
 
-        spec = _rule_spec_from_path([x.decode('utf8') for x in request.postpath])
+        spec = _rule_spec_from_path([x for x in path.split("/")])
 
         requester = yield self.auth.get_user_by_req(request)
         user_id = requester.user.to_string()
@@ -130,7 +130,7 @@ class PushRuleRestServlet(ClientV1RestServlet):
                 raise
 
     @defer.inlineCallbacks
-    def on_GET(self, request):
+    def on_GET(self, request, path):
         requester = yield self.auth.get_user_by_req(request)
         user_id = requester.user.to_string()
 
@@ -141,7 +141,7 @@ class PushRuleRestServlet(ClientV1RestServlet):
 
         rules = format_push_rules_for_user(requester.user, rules)
 
-        path = [x.decode('utf8') for x in request.postpath][1:]
+        path = [x for x in path.split("/")][1:]
 
         if path == []:
             # we're a reference impl: pedantry is our job.
@@ -157,7 +157,7 @@ class PushRuleRestServlet(ClientV1RestServlet):
         else:
             raise UnrecognizedRequestError()
 
-    def on_OPTIONS(self, _):
+    def on_OPTIONS(self, request, path):
         return 200, {}
 
     def notify_user(self, user_id):