Fix stale closure in location update callback + add debug logging

src/app/room/[slug]/page.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useEffect, useState } from 'react';
+import { useEffect, useState, useRef, useCallback } from 'react';
 import { useParams, useRouter } from 'next/navigation';
 import dynamic from 'next/dynamic';
 import { useRoom } from '@/hooks/useRoom';
@@ -8,7 +8,7 @@ import { useLocationSharing } from '@/hooks/useLocationSharing';
 import ParticipantList from '@/components/room/ParticipantList';
 import RoomHeader from '@/components/room/RoomHeader';
 import ShareModal from '@/components/room/ShareModal';
-import type { Participant } from '@/types';
+import type { Participant, ParticipantLocation } from '@/types';
 
 // Dynamic import for map to avoid SSR issues with MapLibre
 const DualMapView = dynamic(() => import('@/components/map/DualMapView'), {
@@ -61,6 +61,26 @@ export default function RoomPage() {
     userEmoji: currentUser?.emoji || '👤',
   });
 
+  // Use refs to avoid stale closures in callbacks
+  const isConnectedRef = useRef(isConnected);
+  const updateLocationRef = useRef(updateLocation);
+
+  useEffect(() => {
+    isConnectedRef.current = isConnected;
+  }, [isConnected]);
+
+  useEffect(() => {
+    updateLocationRef.current = updateLocation;
+  }, [updateLocation]);
+
+  // Stable callback that always uses latest refs
+  const handleLocationUpdate = useCallback((location: ParticipantLocation) => {
+    console.log('Location update received:', location.latitude, location.longitude, 'connected:', isConnectedRef.current);
+    if (isConnectedRef.current) {
+      updateLocationRef.current(location);
+    }
+  }, []);
+
   // Location sharing hook
   const {
     isSharing,
@@ -68,11 +88,7 @@ export default function RoomPage() {
     startSharing,
     stopSharing,
   } = useLocationSharing({
-    onLocationUpdate: (location) => {
-      if (isConnected) {
-        updateLocation(location);
-      }
-    },
+    onLocationUpdate: handleLocationUpdate,
     updateInterval: 5000,
     highAccuracy: true,
   });

src/components/map/MapView.tsx

@@ -101,6 +101,11 @@ export default function MapView({
   useEffect(() => {
     if (!map.current || !mapLoaded) return;
 
+    console.log('MapView: Updating markers for', participants.length, 'participants');
+    participants.forEach((p) => {
+      console.log('  -', p.name, p.id, 'location:', p.location ? `${p.location.latitude}, ${p.location.longitude}` : 'none');
+    });
+
     const currentMarkers = markersRef.current;
     const participantIds = new Set(participants.map((p) => p.id));
 

src/lib/sync.ts

@@ -269,11 +269,15 @@ export class RoomSync {
   }
 
   updateLocation(location: LocationState): void {
+    console.log('RoomSync.updateLocation called:', location.latitude, location.longitude);
     if (this.state.participants[this.participantId]) {
       this.state.participants[this.participantId].location = location;
       this.state.participants[this.participantId].lastSeen = new Date().toISOString();
       this.send({ type: 'location', participantId: this.participantId, location });
+      console.log('Location set for participant:', this.participantId, 'Total participants:', Object.keys(this.state.participants).length);
       this.notifyStateChange();
+    } else {
+      console.warn('Cannot update location - participant not found:', this.participantId);
     }
   }