From bd98315fe31bf8ea8d2f387a07f25f8498650936 Mon Sep 17 00:00:00 2001
From: "claude (blind_chess)" <claude@sethpc.xyz>
Date: Mon, 18 May 2026 20:27:25 -0400
Subject: [PATCH] fix(client): guard phantom-store mutations against unset game
 and no-op move

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 packages/client/src/lib/stores/phantoms.svelte.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/client/src/lib/stores/phantoms.svelte.ts b/packages/client/src/lib/stores/phantoms.svelte.ts
index a2e6ecf..e351e93 100644
--- a/packages/client/src/lib/stores/phantoms.svelte.ts
+++ b/packages/client/src/lib/stores/phantoms.svelte.ts
@@ -38,11 +38,13 @@ function makeStore() {
   }
 
   function place(sq: Square, type: PieceType) {
+    if (!gameId) return;
     state.phantoms = { ...state.phantoms, [sq]: { color: oppColor, type } };
     persist();
   }
 
   function move(from: Square, to: Square) {
+    if (!gameId || from === to) return;
     const p = state.phantoms[from];
     if (!p) return;
     const next = { ...state.phantoms };
@@ -53,6 +55,7 @@ function makeStore() {
   }
 
   function remove(sq: Square) {
+    if (!gameId) return;
     const next = { ...state.phantoms };
     delete next[sq];
     state.phantoms = next;