Implement MSC4069: Inhibit profile propagation (#16636)

MSC: https://github.com/matrix-org/matrix-spec-proposals/pull/4069

4 files changed, 42 insertions, 5 deletions

diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index 9f830e7094..6b9febe5a7 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -419,3 +419,7 @@ class ExperimentalConfig(Config):
         self.msc4028_push_encrypted_events = experimental.get(
             "msc4028_push_encrypted_events", False
         )
+
+        self.msc4069_profile_inhibit_propagation = experimental.get(
+            "msc4069_profile_inhibit_propagation", False
+        )
diff --git a/synapse/handlers/profile.py b/synapse/handlers/profile.py
index 1027fbfd28..e043fd5322 100644
--- a/synapse/handlers/profile.py
+++ b/synapse/handlers/profile.py
@@ -129,6 +129,7 @@ class ProfileHandler:
         new_displayname: str,
         by_admin: bool = False,
         deactivation: bool = False,
+        propagate: bool = True,
     ) -> None:
         """Set the displayname of a user
 
@@ -138,6 +139,7 @@ class ProfileHandler:
             new_displayname: The displayname to give this user.
             by_admin: Whether this change was made by an administrator.
             deactivation: Whether this change was made while deactivating the user.
+            propagate: Whether this change also applies to the user's membership events.
         """
         if not self.hs.is_mine(target_user):
             raise SynapseError(400, "User is not hosted on this homeserver")
@@ -188,7 +190,8 @@ class ProfileHandler:
             target_user.to_string(), profile, by_admin, deactivation
         )
 
-        await self._update_join_states(requester, target_user)
+        if propagate:
+            await self._update_join_states(requester, target_user)
 
     async def get_avatar_url(self, target_user: UserID) -> Optional[str]:
         if self.hs.is_mine(target_user):
@@ -221,6 +224,7 @@ class ProfileHandler:
         new_avatar_url: str,
         by_admin: bool = False,
         deactivation: bool = False,
+        propagate: bool = True,
     ) -> None:
         """Set a new avatar URL for a user.
 
@@ -230,6 +234,7 @@ class ProfileHandler:
             new_avatar_url: The avatar URL to give this user.
             by_admin: Whether this change was made by an administrator.
             deactivation: Whether this change was made while deactivating the user.
+            propagate: Whether this change also applies to the user's membership events.
         """
         if not self.hs.is_mine(target_user):
             raise SynapseError(400, "User is not hosted on this homeserver")
@@ -278,7 +283,8 @@ class ProfileHandler:
             target_user.to_string(), profile, by_admin, deactivation
         )
 
-        await self._update_join_states(requester, target_user)
+        if propagate:
+            await self._update_join_states(requester, target_user)
 
     @cached()
     async def check_avatar_size_and_mime_type(self, mxc: str) -> bool:
diff --git a/synapse/rest/client/profile.py b/synapse/rest/client/profile.py
index 493e1acea0..12d3da1ced 100644
--- a/synapse/rest/client/profile.py
+++ b/synapse/rest/client/profile.py
@@ -13,12 +13,17 @@
 # limitations under the License.
 
 """ This module contains REST servlets to do with profile: /profile/<paths> """
+
 from http import HTTPStatus
 from typing import TYPE_CHECKING, Tuple
 
 from synapse.api.errors import Codes, SynapseError
 from synapse.http.server import HttpServer
-from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from synapse.http.servlet import (
+    RestServlet,
+    parse_boolean,
+    parse_json_object_from_request,
+)
 from synapse.http.site import SynapseRequest
 from synapse.rest.client._base import client_patterns
 from synapse.types import JsonDict, UserID
@@ -27,6 +32,20 @@ if TYPE_CHECKING:
     from synapse.server import HomeServer
 
 
+def _read_propagate(hs: "HomeServer", request: SynapseRequest) -> bool:
+    # This will always be set by the time Twisted calls us.
+    assert request.args is not None
+
+    propagate = True
+    if hs.config.experimental.msc4069_profile_inhibit_propagation:
+        do_propagate = request.args.get(b"org.matrix.msc4069.propagate")
+        if do_propagate is not None:
+            propagate = parse_boolean(
+                request, "org.matrix.msc4069.propagate", default=False
+            )
+    return propagate
+
+
 class ProfileDisplaynameRestServlet(RestServlet):
     PATTERNS = client_patterns("/profile/(?P<user_id>[^/]*)/displayname", v1=True)
     CATEGORY = "Event sending requests"
@@ -80,7 +99,11 @@ class ProfileDisplaynameRestServlet(RestServlet):
                 errcode=Codes.BAD_JSON,
             )
 
-        await self.profile_handler.set_displayname(user, requester, new_name, is_admin)
+        propagate = _read_propagate(self.hs, request)
+
+        await self.profile_handler.set_displayname(
+            user, requester, new_name, is_admin, propagate=propagate
+        )
 
         return 200, {}
 
@@ -135,8 +158,10 @@ class ProfileAvatarURLRestServlet(RestServlet):
                 400, "Missing key 'avatar_url'", errcode=Codes.MISSING_PARAM
             )
 
+        propagate = _read_propagate(self.hs, request)
+
         await self.profile_handler.set_avatar_url(
-            user, requester, new_avatar_url, is_admin
+            user, requester, new_avatar_url, is_admin, propagate=propagate
         )
 
         return 200, {}
diff --git a/synapse/rest/client/versions.py b/synapse/rest/client/versions.py
index f4d19e0470..54c01bb739 100644
--- a/synapse/rest/client/versions.py
+++ b/synapse/rest/client/versions.py
@@ -129,6 +129,8 @@ class VersionsRestServlet(RestServlet):
                     "org.matrix.msc3981": self.config.experimental.msc3981_recurse_relations,
                     # Adds support for deleting account data.
                     "org.matrix.msc3391": self.config.experimental.msc3391_enabled,
+                    # Allows clients to inhibit profile update propagation.
+                    "org.matrix.msc4069": self.config.experimental.msc4069_profile_inhibit_propagation,
                 },
             },
         )