From 82b23d9a1390f7e9553df4e8a001a48f37072920 Mon Sep 17 00:00:00 2001
From: Benoit Marty <benoit@matrix.org>
Date: Tue, 24 Nov 2020 06:08:39 +0100
Subject: [PATCH] Ensure we push only clean m.room.canonical_alias event

---
 .../internal/session/room/state/DefaultStateService.kt    | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/state/DefaultStateService.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/state/DefaultStateService.kt
index 96fb71503a..3d6e869607 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/state/DefaultStateService.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/state/DefaultStateService.kt
@@ -111,7 +111,13 @@ internal class DefaultStateService @AssistedInject constructor(@Assisted private
                 eventType = EventType.STATE_ROOM_CANONICAL_ALIAS,
                 body = RoomCanonicalAliasContent(
                         canonicalAlias = alias,
-                        alternativeAliases = altAliases.distinct()
+                        alternativeAliases = altAliases
+                                // Ensure there is no duplicate
+                                .distinct()
+                                // Ensure the canonical alias is not also included in the alt alias
+                                .minus(listOfNotNull(alias))
+                                // Sort for the cleanup
+                                .sorted()
                 ).toContent(),
                 callback = callback,
                 stateKey = null