diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 0a895bba48..7ef4701b13 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -81,6 +81,8 @@ class RoomVersion:
msc2716_historical = attr.ib(type=bool)
# MSC2716: Adds support for redacting "insertion", "chunk", and "marker" events
msc2716_redactions = attr.ib(type=bool)
+ # MSC2716: Adds support for events with no `prev_events` but with some `auth_events`
+ msc2716_empty_prev_events = attr.ib(type=bool)
class RoomVersions:
@@ -99,6 +101,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V2 = RoomVersion(
"2",
@@ -115,6 +118,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V3 = RoomVersion(
"3",
@@ -131,6 +135,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V4 = RoomVersion(
"4",
@@ -147,6 +152,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V5 = RoomVersion(
"5",
@@ -163,6 +169,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V6 = RoomVersion(
"6",
@@ -179,6 +186,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
MSC2176 = RoomVersion(
"org.matrix.msc2176",
@@ -195,6 +203,7 @@ class RoomVersions:
msc2403_knocking=False,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V7 = RoomVersion(
"7",
@@ -211,6 +220,7 @@ class RoomVersions:
msc2403_knocking=True,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V8 = RoomVersion(
"8",
@@ -227,6 +237,7 @@ class RoomVersions:
msc2403_knocking=True,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
V9 = RoomVersion(
"9",
@@ -243,6 +254,7 @@ class RoomVersions:
msc2403_knocking=True,
msc2716_historical=False,
msc2716_redactions=False,
+ msc2716_empty_prev_events=False,
)
MSC2716v3 = RoomVersion(
"org.matrix.msc2716v3",
@@ -259,6 +271,24 @@ class RoomVersions:
msc2403_knocking=True,
msc2716_historical=True,
msc2716_redactions=True,
+ msc2716_empty_prev_events=False,
+ )
+ MSC2716v4 = RoomVersion(
+ "org.matrix.msc2716v4",
+ RoomDisposition.UNSTABLE,
+ EventFormatVersions.V3,
+ StateResolutionVersions.V2,
+ enforce_key_validity=True,
+ special_case_aliases_auth=False,
+ strict_canonicaljson=True,
+ limit_notifications_power_levels=True,
+ msc2176_redaction_rules=False,
+ msc3083_join_rules=False,
+ msc3375_redaction_rules=False,
+ msc2403_knocking=True,
+ msc2716_historical=True,
+ msc2716_redactions=True,
+ msc2716_empty_prev_events=True,
)
@@ -276,6 +306,7 @@ KNOWN_ROOM_VERSIONS: Dict[str, RoomVersion] = {
RoomVersions.V8,
RoomVersions.V9,
RoomVersions.MSC2716v3,
+ RoomVersions.MSC2716v4,
)
}
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 1b872281f6..d6f0b99f58 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -949,18 +949,24 @@ class EventCreationHandler:
else:
prev_event_ids = await self.store.get_prev_events_for_room(builder.room_id)
- # we now ought to have some prev_events (unless it's a create event).
- #
- # do a quick sanity check here, rather than waiting until we've created the
+ # Do a quick sanity check here, rather than waiting until we've created the
# event and then try to auth it (which fails with a somewhat confusing "No
# create event in auth events")
- assert (
- builder.type == EventTypes.Create
- or len(prev_event_ids) > 0
- # Allow an event to have empty list of prev_event_ids
- # only if it has auth_event_ids.
- or (auth_event_ids and len(auth_event_ids) > 0)
- ), "Attempting to create an event with no prev_events or auth_event_ids"
+ room_version_obj = await self.store.get_room_version(builder.room_id)
+ if room_version_obj.msc2716_empty_prev_events:
+ # We allow events with no `prev_events` but it better have some `auth_events`
+ assert (
+ builder.type == EventTypes.Create
+ or len(prev_event_ids) > 0
+ # Allow an event to have empty list of prev_event_ids
+ # only if it has auth_event_ids.
+ or (auth_event_ids and len(auth_event_ids) > 0)
+ ), "Attempting to create an event with no prev_events or auth_event_ids"
+ else:
+ # we now ought to have some prev_events (unless it's a create event).
+ assert (
+ builder.type == EventTypes.Create or len(prev_event_ids) > 0
+ ), "Attempting to create an event with no prev_events"
event = await builder.build(
prev_event_ids=prev_event_ids,
|
