From 54f049eeccd6f4f02a692445cd9470c44da427ba Mon Sep 17 00:00:00 2001
From: Greg Pomerantz <gmp@wow.st>
Date: Wed, 9 Sep 2026 16:43:47 -0400
Subject: [PATCH] Enforce the date-sync invariant in commit/restore, not just
 the flight tool
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

redateStaysAndPlaces() now runs in commit() (before the snapshot, so
history stores consistent pairs) and in restore(). Any present or future
edit that changes day dates keeps stays/places/booking strings in sync
for free; consistent plans are an idempotent no-op. apply_flight_anchors
no longer calls it directly — commit is the single enforcement point.
enterTrip's load-time self-heal stays for plans persisted by older code.
---
 mock/app.js | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/mock/app.js b/mock/app.js
index 870cbf5..6983713 100644
--- a/mock/app.js
+++ b/mock/app.js
@@ -413,12 +413,10 @@ const TOOLS = {
     }
     last.wakingHours = Math.max(1, Math.round((depMin - last.startMin) / 60));
 
-    // 5) sync the date-carrying neighbours (stays / places / hotel bookings)
-    redateStaysAndPlaces();
-
-    // 6) commit (persisted immediately — this is the edit we must never lose)
-    //    + re-render every date-bearing UI piece (renderAll alone only covers
-    //    rail + map, which left tabs, chips and title showing old dates)
+    // 5) commit (persisted immediately — this is the edit we must never lose;
+    //    commit() also re-syncs stays/places/booking dates to the new day
+    //    dates) + re-render every date-bearing UI piece (renderAll alone only
+    //    covers rail + map, which left tabs, chips and title showing old dates)
     ids.forEach(id => rebuildLegs(days[id]));
     commit('[flight] re-anchored around booked arrival + departure');
     persistTrip(true);
@@ -1659,6 +1657,11 @@ function recentHistory() {
   return out;
 }
 const commit = (label) => {
+  // invariant for every edit, not just flight re-anchoring: the date-carrying
+  // neighbours (stays, places, hotel booking strings) must track the day
+  // dates. Idempotent — a consistent plan is a no-op. Runs before the
+  // snapshot so history stores consistent pairs.
+  redateStaysAndPlaces();
   history = history.slice(0, hIdx + 1);      // drop any redo branch
   history.push({ v: ++version, label, at: Date.now(), days: deep(days), stays: deep(stays), bookings: deep(M.trip.bookings), title: M.trip.title });
   hIdx = history.length - 1;
@@ -1674,6 +1677,7 @@ function restore(idx, silent) {
   staySeq = stays.reduce((m, o) => Math.max(m, +String(o.id).replace(/\D/g, '') || 0), 1);
   if (s.bookings) M.trip.bookings = deep(s.bookings);
   if (s.title != null) M.trip.title = s.title;
+  redateStaysAndPlaces();   // old-era snapshots may hold inconsistent pairs
   closeDiscover(); closeL3();
   rebuildLegs(day);   // snapshots may predate route enrichment — re-upgrade legs
   renderHotelMks(); renderBaseChip();