From 85a43f4167b5e775f7c3afe96d71137818561272 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Mon, 17 Sep 2018 13:19:00 +0100
Subject: Return a 404 when deleting unknown room alias

As per https://github.com/matrix-org/matrix-doc/issues/1675

Fixes https://github.com/matrix-org/synapse/issues/2782
---
 synapse/handlers/directory.py | 19 ++++++++++++++++---
 synapse/storage/directory.py  |  1 -
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index ef866da1b6..c745e6740b 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -20,7 +20,14 @@ import string
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
-from synapse.api.errors import AuthError, CodeMessageException, Codes, SynapseError
+from synapse.api.errors import (
+    AuthError,
+    CodeMessageException,
+    Codes,
+    NotFoundError,
+    StoreError,
+    SynapseError,
+)
 from synapse.types import RoomAlias, UserID, get_domain_from_id
 
 from ._base import BaseHandler
@@ -109,7 +116,13 @@ class DirectoryHandler(BaseHandler):
     def delete_association(self, requester, user_id, room_alias):
         # association deletion for human users
 
-        can_delete = yield self._user_can_delete_alias(room_alias, user_id)
+        try:
+            can_delete = yield self._user_can_delete_alias(room_alias, user_id)
+        except StoreError as e:
+            if e.code == 404:
+                raise NotFoundError("Unknown room alias")
+            raise
+
         if not can_delete:
             raise AuthError(
                 403, "You don't have permission to delete the alias.",
@@ -320,7 +333,7 @@ class DirectoryHandler(BaseHandler):
     def _user_can_delete_alias(self, alias, user_id):
         creator = yield self.store.get_room_alias_creator(alias.to_string())
 
-        if creator and creator == user_id:
+        if creator == user_id:
             defer.returnValue(True)
 
         is_admin = yield self.auth.is_server_admin(UserID.from_string(user_id))
diff --git a/synapse/storage/directory.py b/synapse/storage/directory.py
index 808194236a..cfb687cb53 100644
--- a/synapse/storage/directory.py
+++ b/synapse/storage/directory.py
@@ -75,7 +75,6 @@ class DirectoryWorkerStore(SQLBaseStore):
             },
             retcol="creator",
             desc="get_room_alias_creator",
-            allow_none=True
         )
 
     @cached(max_entries=5000)
-- 
cgit 1.4.1


From c1ae6b1bce61fecda91aa6ab8a51d152418cf79e Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Mon, 17 Sep 2018 13:21:08 +0100
Subject: changelog

---
 changelog.d/3889.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/3889.bugfix

diff --git a/changelog.d/3889.bugfix b/changelog.d/3889.bugfix
new file mode 100644
index 0000000000..e976425987
--- /dev/null
+++ b/changelog.d/3889.bugfix
@@ -0,0 +1 @@
+Fix 500 error when deleting unknown room alias
-- 
cgit 1.4.1


From f75b9961c6c782d2ca4586782aa5cd2c0ae9a5b2 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Mon, 17 Sep 2018 16:52:02 +0100
Subject: Reinstate missing null check

---
 synapse/handlers/directory.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index c745e6740b..18741c5fac 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -333,7 +333,7 @@ class DirectoryHandler(BaseHandler):
     def _user_can_delete_alias(self, alias, user_id):
         creator = yield self.store.get_room_alias_creator(alias.to_string())
 
-        if creator == user_id:
+        if creator is not None and creator == user_id:
             defer.returnValue(True)
 
         is_admin = yield self.auth.is_server_admin(UserID.from_string(user_id))
-- 
cgit 1.4.1