From a9a18fc5f07c55f2f59289df5ddccdfebeab7793 Mon Sep 17 00:00:00 2001
From: Ginger <ginger@gingershaped.computer>
Date: Wed, 22 Apr 2026 10:41:01 -0400
Subject: [PATCH] fix: Re-add support for custom room IDs

---
 src/api/client/room/create.rs | 22 ++++++++++++++++------
 src/api/router/args.rs        |  6 +++---
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/api/client/room/create.rs b/src/api/client/room/create.rs
index 1eb5e432c..6cb907871 100644
--- a/src/api/client/room/create.rs
+++ b/src/api/client/room/create.rs
@@ -9,8 +9,8 @@
 use conduwuit_service::{Services, appservice::RegistrationInfo};
 use futures::FutureExt;
 use ruma::{
-	CanonicalJsonObject, Int, MilliSecondsSinceUnixEpoch, OwnedRoomAliasId, OwnedRoomId,
-	OwnedUserId, RoomAliasId, RoomId, RoomVersionId, UserId,
+	CanonicalJsonObject, CanonicalJsonValue, Int, MilliSecondsSinceUnixEpoch, OwnedRoomAliasId,
+	OwnedRoomId, OwnedUserId, RoomAliasId, RoomId, RoomVersionId, UserId,
 	api::client::room::{self, create_room},
 	assign,
 	events::{
@@ -87,7 +87,19 @@ pub(crate) async fn create_room_route(
 	let room_version_rules = room_version.rules().unwrap();
 
 	let room_id: Option<OwnedRoomId> = match room_version_rules.room_id_format {
-		| RoomIdFormatVersion::V1 => Some(RoomId::new_v1(services.globals.server_name())),
+		| RoomIdFormatVersion::V1 => {
+			// Check for custom room ID field
+			if let Some(CanonicalJsonValue::String(room_id)) =
+				body.json_body.as_ref().unwrap().get("room_id")
+			{
+				Some(
+					RoomId::parse(room_id)
+						.map_err(|_| err!(Request(BadJson("Malformed custom room ID"))))?,
+				)
+			} else {
+				Some(RoomId::new_v1(services.globals.server_name()))
+			}
+		},
 		| _ => None,
 	};
 
@@ -235,10 +247,8 @@ pub(crate) async fn create_room_route(
 		.json_body
 		.as_ref()
 		.unwrap()
-		.as_object()
-		.unwrap()
 		.get("origin_server_ts")
-		.and_then(ruma::CanonicalJsonValue::as_integer)
+		.and_then(CanonicalJsonValue::as_integer)
 		.map(Into::into)
 		.and_then(|value: i64| value.try_into().ok())
 		.map(MilliSecondsSinceUnixEpoch);
diff --git a/src/api/router/args.rs b/src/api/router/args.rs
index 26927504b..c7a57b918 100644
--- a/src/api/router/args.rs
+++ b/src/api/router/args.rs
@@ -7,7 +7,7 @@
 };
 use conduwuit::{Error, Result, err};
 use ruma::{
-	CanonicalJsonValue, DeviceId, OwnedDeviceId, OwnedServerName, OwnedUserId, ServerName,
+	CanonicalJsonObject, DeviceId, OwnedDeviceId, OwnedServerName, OwnedUserId, ServerName,
 	UserId, api::IncomingRequest,
 };
 use serde::Deserialize;
@@ -47,7 +47,7 @@ pub(crate) struct Args<T> {
 
 	/// Parsed JSON content.
 	/// None when body is not a valid string
-	pub(crate) json_body: Option<CanonicalJsonValue>,
+	pub(crate) json_body: Option<CanonicalJsonObject>,
 }
 
 impl<T> Args<T>
@@ -127,7 +127,7 @@ async fn from_request(
 		};
 
 		// Make a JSON copy of the body for use in handlers
-		let json_body = serde_json::from_slice::<CanonicalJsonValue>(&body).ok();
+		let json_body = serde_json::from_slice::<CanonicalJsonObject>(&body).ok();
 
 		// Extract the query parameters and path
 		let Path(path): Path<Vec<String>> = parts.extract().await?;