Global hash strip: suppress re-scan on anchor-only URL changes

background.js

@@ -639,24 +639,42 @@ async function persistTabResult(tab, result) {
   } catch {}
 }
 
+// URL fragment (hash) never affects server response or our ID extraction. Strip it
+// when comparing URLs so in-page anchor jumps (e.g. `#gallery-1`, `#gallery-2`) don't
+// invalidate the tab cache or re-trigger scans. See exoticaz.to gallery navigation.
+function stripHash(url) {
+  if (typeof url !== "string") return url;
+  const i = url.indexOf("#");
+  return i === -1 ? url : url.slice(0, i);
+}
+
+// Tracks the last full URL we saw per tab so we can detect hash-only changes
+// (which Chrome still reports via `chrome.tabs.onUpdated` with `changeInfo.url`).
+const tabLastUrl = new Map(); // tabId -> last full url seen
+
 async function getTabResult(tab) {
   if (!tab || tab.id == null) return null;
   try {
     const got = await chrome.storage.session.get(tabCacheKey(tab.id));
     const entry = got[tabCacheKey(tab.id)];
     if (!entry) return null;
-    if (entry.url !== (tab.url || "")) return null;
+    if (stripHash(entry.url) !== stripHash(tab.url || "")) return null;
     return entry;
   } catch { return null; }
 }
 
 chrome.tabs.onUpdated.addListener((tabId, changeInfo) => {
-  if (changeInfo.url) chrome.storage.session.remove(tabCacheKey(tabId));
+  if (!changeInfo.url) return;
+  const prev = tabLastUrl.get(tabId);
+  // Hash-only change → keep the cached result; same page, just a fragment jump.
+  if (prev && stripHash(prev) === stripHash(changeInfo.url)) return;
+  chrome.storage.session.remove(tabCacheKey(tabId));
 });
 chrome.tabs.onRemoved.addListener((tabId) => {
   stopBadgeSpinner(tabId);
   chrome.storage.session.remove(tabCacheKey(tabId));
   lastAutoCheck.delete(tabId);
+  tabLastUrl.delete(tabId);
   const t = pendingSpaTimer.get(tabId);
   if (t) { clearTimeout(t); pendingSpaTimer.delete(tabId); }
 });
@@ -999,6 +1017,7 @@ chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
   if (changeInfo.status === "complete") {
     const t = pendingSpaTimer.get(tabId);
     if (t) { clearTimeout(t); pendingSpaTimer.delete(tabId); }
+    tabLastUrl.set(tabId, tab.url);
     maybeAutoCheck(tabId, tab, "complete");
     return;
   }
@@ -1006,6 +1025,11 @@ chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
   // the page has a chance to update its title/DOM, and so a real reload (which
   // also emits a url change before complete) doesn't double-fire.
   if (typeof changeInfo.url === "string") {
+    const prevUrl = tabLastUrl.get(tabId);
+    tabLastUrl.set(tabId, changeInfo.url);
+    // Hash-only change (e.g. `#gallery-2` anchor jump) is purely client-side UI
+    // state. Suppress the SPA scan trigger so anchor navigation doesn't re-fire.
+    if (prevUrl && stripHash(prevUrl) === stripHash(changeInfo.url)) return;
     const prev = pendingSpaTimer.get(tabId);
     if (prev) clearTimeout(prev);
     const handle = setTimeout(() => {