From eb91a2f8565250ad14f22b76d1d34bb4829965e7 Mon Sep 17 00:00:00 2001
From: jay <thejayman77@gmail.com>
Date: Mon, 8 Jun 2026 09:11:24 -0400
Subject: [PATCH] Nav hardening: app-safe deep-link Back + stale-load guard on
 Today
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Per Codex audit follow-ups:
* Track in-app navigation depth (forward goto/link increments, popstate
  unwinds, clamped at 0) and base the in-page Back on it instead of
  history.length. A direct deep link (email/social/article) now sends the
  in-page Back to Highlights rather than out of the site.
* Apply the same stale-load guard to the Today/Highlights path that feed views
  have, and only scroll-to-top when the load is still current — avoids stale
  error/scroll state during quick navigation.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 frontend/src/routes/+page.svelte | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/frontend/src/routes/+page.svelte b/frontend/src/routes/+page.svelte
index fd25d75..b11cd05 100644
--- a/frontend/src/routes/+page.svelte
+++ b/frontend/src/routes/+page.svelte
@@ -236,9 +236,13 @@
     if (source) sourceNames = { ...sourceNames, [source.id]: source.name };
     navigate(key);
   }
+  // How many forward in-app navigations deep we are from the landing entry, so
+  // the in-page Back stays INSIDE the app even when someone deep-links in from
+  // email/social/an article (history.length can't tell us that).
+  let appNavDepth = 0;
   function goBack() {
-    if (typeof history !== 'undefined' && history.length > 1) history.back();
-    else goto(urlForView('today'));
+    if (appNavDepth > 0 && typeof history !== 'undefined') history.back();
+    else goto(urlForView('today')); // landed here directly → app-safe Highlights
   }
 
   // Load the data for a view. Called by afterNavigate (URL-driven: in-app goto,
@@ -251,6 +255,7 @@
     try {
       if (key === 'today') {
         await loadToday(fresh);
+        if (seq !== loadSeq) return; // a newer navigation superseded this one
       } else {
         const items = (await getJSON(feedUrl(key, 0))).items;
         if (seq !== loadSeq) return;
@@ -264,13 +269,17 @@
     } catch (e) {
       if (seq === loadSeq) error = 'Something went quiet — could not reach the feed.';
     }
-    if (typeof window !== 'undefined') window.scrollTo({ top: 0, behavior: 'smooth' });
+    if (seq === loadSeq && typeof window !== 'undefined') window.scrollTo({ top: 0, behavior: 'smooth' });
   }
 
   // Every URL change (in-app goto, browser back/forward, link) reloads the view.
   // The initial 'enter' is handled by onMount, after its data deps are fetched.
   afterNavigate((nav) => {
     if (nav.type === 'enter') return;
+    // Forward in-app nav deepens the stack; back/forward (popstate) unwinds it.
+    // Clamped at 0, so an out-of-app landing keeps Back app-safe (→ Highlights).
+    if (nav.type === 'goto' || nav.type === 'link') appNavDepth += 1;
+    else if (nav.type === 'popstate') appNavDepth = Math.max(0, appNavDepth - 1);
     loadView(selected);
   });