Feed: closing a full-screen picture leaves the feed where it was. The scroll memory that puts a reader back on the row they left when Back closes a thread or profile fired on every history pop, and a remembered place goes stale whenever its page is left another way (the Feed button from a thread), so a photo's × jumped the feed to wherever an earlier thread had been opened from, or to its top (Adam's recording, 2026-10-11 22:31, at the 10 s mark; reproduced on his tab: 2500 → 22361). Now the place is restored only when a pop actually leaves a thread or profile — the page being left is read in a capture-phase popstate listener, before the app's own handler re-renders — and the entries above the one it matches are dropped as stale. tools/lightbox-scroll-test.js (stale place from a thread left by the Feed button, a picture opened and closed, Back out of a thread still landing on its row). avatar-profile-test fails on HEAD before this too.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

1 files changed, 21 insertions, 9 deletions

diff --git a/src/features/messages.js b/src/features/messages.js
index 64e36c5..7c81d27 100644
--- a/src/features/messages.js
+++ b/src/features/messages.js
@@ -3931,15 +3931,27 @@ export function messagesFeature(ctx) {
     pageReturn.push({ key, y });
     if (pageReturn.length > 20) pageReturn.shift();
   }
-  if (typeof window !== 'undefined') window.addEventListener('popstate', () => {
-    const top = pageReturn[pageReturn.length - 1];
-    if (!top || pageKey() === top.key) return;
-    pageReturn.pop();
-    const y = top.y;
-    // twice: the page under it may paint its rows a frame late
-    requestAnimationFrame(() => { try { window.scrollTo(0, y); } catch {}
-      requestAnimationFrame(() => { try { if (Math.abs(window.scrollY - y) > 2) window.scrollTo(0, y); } catch {} }); });
-  });
+  // Only Back OUT OF a profile or thread puts the reader back. Any other
+  // pop — a full-screen picture closing, a sheet — leaves the page where it
+  // is. It used to restore the newest remembered place on every pop, and a
+  // place goes stale whenever its page is left some other way (the Feed
+  // button from a thread): a photo's × then jumped the feed to wherever an
+  // earlier thread had been opened from, or to its top.
+  let pageLeft = ''; // the page a pop is leaving, read before the app restores the entry under it
+  if (typeof window !== 'undefined') {
+    window.addEventListener('popstate', () => { pageLeft = pageKey(); }, true); // capture: before the app's own handler re-renders
+    window.addEventListener('popstate', () => {
+      const left = pageLeft; pageLeft = '';
+      if (!left || pageKey() === left) return;
+      const i = pageReturn.map((e) => e.key).lastIndexOf(left);
+      if (i < 0) return;
+      const y = pageReturn[i].y;
+      pageReturn.length = i; // this entry, and anything stale above it
+      // twice: the page under it may paint its rows a frame late
+      requestAnimationFrame(() => { try { window.scrollTo(0, y); } catch {}
+        requestAnimationFrame(() => { try { if (Math.abs(window.scrollY - y) > 2) window.scrollTo(0, y); } catch {} }); });
+    });
+  }
   function openProfile(pk) {
     rememberPlace('p:' + pk);
     ui.profilePk = pk;