Bug #15510: Detach event watchers when finished

src/chrome/content/tor-circuit-display.js

@@ -129,7 +129,7 @@ let getCircuitStatusByID = function* (aController, circuitID) {
 // corresponding circuit. Whenever the first stream on a new circuit is seen,
 // looks up u+p and records the node data in the credentialsToNodeDataMap.
 let collectIsolationData = function (aController) {
-  aController.watchEvent(
+  return aController.watchEvent(
     "STREAM",
     streamEvent => streamEvent.StreamStatus === "SENTCONNECT",
     streamEvent => Task.spawn(function* () {
@@ -313,10 +313,13 @@ let syncDisplayWithSelectedTab = (function() {
 // A reference to this function (called createTorCircuitDisplay) is exported as a global.
 let setupDisplay = function (host, port, password, enablePrefName) {
   let myController = null,
+      stopCollectingIsolationData = null,
       stop = function() {
         if (myController) {
           syncDisplayWithSelectedTab(false);
-          myController.close();
+          if (stopCollectingIsolationData) {
+	    stopCollectingIsolationData();
+          }
           myController = null;
         }
       },
@@ -326,16 +329,20 @@ let setupDisplay = function (host, port, password, enablePrefName) {
             // An error has occurred.
             logger.eclog(5, err);
             logger.eclog(5, "Disabling tor display circuit because of an error.");
+            myController.close();
             stop();
           });
           syncDisplayWithSelectedTab(true);
-          collectIsolationData(myController);
+          stopCollectingIsolationData = collectIsolationData(myController);
        }
      };
   try {
     let unbindPref = bindPrefAndInit(enablePrefName, on => { if (on) start(); else stop(); });
     // When this chrome window is unloaded, we need to unbind the pref.
-    window.addEventListener("unload", unbindPref);
+    window.addEventListener("unload", function () {
+      unbindPref();
+      stop();
+    });
   } catch (e) {
     logger.eclog(5, "Error: " + e.message + "\n" + e.stack);
   }

src/modules/tor-control-port.js

@@ -606,9 +606,10 @@ event.messageToData = function (type, message) {
 
 // __event.watchEvent(controlSocket, type, filter, onData)__.
 // Watches for a particular type of event. If filter(data) returns true, the event's
-// data is pass to the onData callback.
+// data is pass to the onData callback. Returns a zero arg function that
+// stops watching the event.
 event.watchEvent = function (controlSocket, type, filter, onData) {
-  controlSocket.addNotificationCallback(new RegExp("^650." + type, "i"),
+  return controlSocket.addNotificationCallback(new RegExp("^650." + type, "i"),
     function (message) {
       let data = event.messageToData(type, message);
       if (filter === null || filter(data)) {
@@ -635,9 +636,8 @@ tor.controller = function (host, port, password, onError) {
   return { getInfo : key => info.getInfo(socket, key),
            getInfoMultiple : keys => info.getInfoMultiple(socket, keys),
            getConf : key => info.getConf(socket, key),
-           watchEvent : function (type, filter, onData) {
-             event.watchEvent(socket, type, filter, onData);
-           },
+           watchEvent : (type, filter, onData) =>
+                          event.watchEvent(socket, type, filter, onData),
            isOpen : () => isOpen,
            close : () => { isOpen = false; socket.close(); }
          };