Maintain order in role related functions.

discord/client.py

@@ -2021,11 +2021,11 @@ class Client:
         yield from response.release()
 
     @asyncio.coroutine
-    def _replace_roles(self, member, *roles):
+    def _replace_roles(self, member, roles):
         url = '{0}/{1.server.id}/members/{1.id}'.format(endpoints.SERVERS, member)
 
         payload = {
-            'roles': list(roles)
+            'roles': roles
         }
 
         r = yield from aiohttp.patch(url, headers=self.headers, data=utils.to_json(payload), loop=self.loop)
@@ -2059,8 +2059,8 @@ class Client:
             Adding roles failed.
         """
 
-        new_roles = {role.id for role in itertools.chain(member.roles, roles)}
-        yield from self._replace_roles(member, *new_roles)
+        new_roles = utils._unique(itertools.chain(member.roles, roles))
+        yield from self._replace_roles(member, new_roles)
 
     @asyncio.coroutine
     def remove_roles(self, member, *roles):
@@ -2086,9 +2086,16 @@ class Client:
         HTTPException
             Removing roles failed.
         """
-        new_roles = {role.id for role in member.roles}
-        new_roles = new_roles.difference(role.id for role in roles)
-        yield from self._replace_roles(member, *new_roles)
+        new_roles = [x.id for x in member.roles]
+        remove = []
+        for index, role in enumerate(roles):
+            if role.id in new_roles:
+                remove.append(index)
+
+        for index in reversed(remove):
+            del new_roles[index]
+
+        yield from self._replace_roles(member, new_roles)
 
     @asyncio.coroutine
     def replace_roles(self, member, *roles):
@@ -2120,8 +2127,8 @@ class Client:
             Removing roles failed.
         """
 
-        new_roles = {role.id for role in roles}
-        yield from self._replace_roles(member, *new_roles)
+        new_roles = utils._unique(roles)
+        yield from self._replace_roles(member, new_roles)
 
     @asyncio.coroutine
     def create_role(self, server, **fields):

discord/utils.py

@@ -137,6 +137,11 @@ def get(iterable, **attrs):
     return find(predicate, iterable)
 
 
+def _unique(iterable):
+    seen = set()
+    adder = seen.add
+    return [x for x in iterable if not (x in seen or adder(x))]
+
 def _null_event(*args, **kwargs):
     pass