Tell host to unshare project when last guest leaves

crates/collab/src/rpc.rs

@@ -634,6 +634,7 @@ impl Server {
         {
             let mut state = self.store_mut().await;
             project = state.leave_project(sender_id, project_id)?;
+            let unshare = project.connection_ids.len() <= 1;
             broadcast(sender_id, project.connection_ids, |conn_id| {
                 self.peer.send(
                     conn_id,
@@ -643,6 +644,12 @@ impl Server {
                     },
                 )
             });
+            if unshare {
+                self.peer.send(
+                    project.host_connection_id,
+                    proto::ProjectUnshared { project_id },
+                )?;
+            }
         }
         self.update_user_contacts(project.host_user_id).await?;
         Ok(())

crates/collab/src/rpc/store.rs

@@ -58,6 +58,7 @@ pub struct RemovedConnectionState {
 pub struct LeftProject {
     pub connection_ids: Vec<ConnectionId>,
     pub host_user_id: UserId,
+    pub host_connection_id: ConnectionId,
 }
 
 #[derive(Copy, Clone)]
@@ -504,6 +505,7 @@ impl Store {
 
         Ok(LeftProject {
             connection_ids: project.connection_ids(),
+            host_connection_id: project.host_connection_id,
             host_user_id: project.host_user_id,
         })
     }