From 2c8b259958b1985299bb98700d7fb6db15ab3930 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Mon, 7 Feb 2022 15:29:47 -0500
Subject: [PATCH 1/2] Revert "Partially revert #11602 to prevent webclient
 overriding client resource (#11764)"

This reverts commit d93ec0a0ba5f6d2fbf2bc321086d4ad4c03136e0.
---
 synapse/app/homeserver.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 24d55b049488..66e1a213319c 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -26,6 +26,7 @@
 import synapse.config.logger
 from synapse import events
 from synapse.api.urls import (
+    CLIENT_API_PREFIX,
     FEDERATION_PREFIX,
     LEGACY_MEDIA_PREFIX,
     MEDIA_R0_PREFIX,
@@ -195,13 +196,7 @@ def _configure_named_resource(
 
             resources.update(
                 {
-                    "/_matrix/client/api/v1": client_resource,
-                    "/_matrix/client/r0": client_resource,
-                    "/_matrix/client/v1": client_resource,
-                    "/_matrix/client/v3": client_resource,
-                    "/_matrix/client/unstable": client_resource,
-                    "/_matrix/client/v2_alpha": client_resource,
-                    "/_matrix/client/versions": client_resource,
+                    CLIENT_API_PREFIX: client_resource,
                     "/.well-known": well_known_resource(self),
                     "/_synapse/admin": AdminRestResource(self),
                     **build_synapse_client_resource_tree(self),

From c809ded7757882cc0b6fcadd276ce8e773da9194 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <patrickc@matrix.org>
Date: Mon, 7 Feb 2022 15:34:28 -0500
Subject: [PATCH 2/2] Newsfragment

---
 changelog.d/11930.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/11930.bugfix

diff --git a/changelog.d/11930.bugfix b/changelog.d/11930.bugfix
new file mode 100644
index 000000000000..e0dfbf1a1520
--- /dev/null
+++ b/changelog.d/11930.bugfix
@@ -0,0 +1 @@
+Fix a long-standing bug that some unknown endpoints would return HTML error pages instead of JSON `M_UNRECOGNIZED` errors.