From 88c84f221feb1dc77664d757051e0766099f18e1 Mon Sep 17 00:00:00 2001
From: Ginger <ginger@gingershaped.computer>
Date: Wed, 31 Dec 2025 15:25:48 -0500
Subject: [PATCH] chore: Add comment and warning to unhappy path

---
 src/api/client/membership/leave.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/api/client/membership/leave.rs b/src/api/client/membership/leave.rs
index 2ed9c22a..b3687612 100644
--- a/src/api/client/membership/leave.rs
+++ b/src/api/client/membership/leave.rs
@@ -179,6 +179,17 @@ pub async fn leave_room(
 					.state_cache
 					.left_state(user_id, room_id)
 					.await
+					.inspect_err(|err| {
+						// `left_state` may return an Err if the user _is_ in the room they're
+						// trying to leave, but the membership cache is incorrect and
+						// they're cached as being joined. In this situation
+						// we save a `None` to the `roomuserid_leftcount` table, which generates
+						// and sends a dummy leave to the client.
+						warn!(
+							"Trying to leave room not cached as leave, sending dummy leave \
+							 event to client"
+						);
+					})
 					.unwrap_or_default()
 			},
 		}