Temporary settings survival more resilient and compatible with Fenix.

src/bg/LifeCycle.js

@@ -75,26 +75,43 @@ var LifeCycle = (() => {
         unrestrictedTabs: [...ns.unrestrictedTabs]
       }));
 
+      try {
         await new Promise((resolve, reject) => {
+          let done = false;
           let l = async (tabId, changeInfo) => {
+            if (done || tabId !== tab.id) return;
             debug("Survival tab updating", changeInfo);
             if (changeInfo.status !== "complete") return;
             try {
               await Messages.send("store", {url, data: toBase64(new Uint8Array(cypherText))}, {tabId, frameId: 0});
+              done = true;
               resolve();
               debug("Survival tab updated");
-            browser.tabs.onUpdated.removeListener(l);
             } catch (e) {
               if (!Messages.isMissingEndpoint(e)) {
                 error(e, "Survival tab failed");
                 reject(e);
               } // otherwise we keep waiting for further updates from the tab until content script is ready to answer
+              return false;
             };
+            return true;
+          };
+
+          try {
+            browser.tabs.onUpdated.addListener(l);
+          } catch (e) {
+            reject(e);
           }
-        browser.tabs.onUpdated.addListener(l, {tabId});
         });
+
         await Storage.set("local", { "updateInfo": {key, iv: toBase64(iv), tabId}});
+        tabId = -1;
         debug("Ready to reload...", await Storage.get("local", "updateInfo"));
+      } finally {
+        if (tabId !== -1 && !ns.local.debug) {
+          browser.tabs.remove(tabId); // cleanup on failure unless we want to debug a post-mortem
+        }
+      }
     },
 
     async retrieveAndDestroy() {