Issue 3224 - Unbreak filter assistant

lib/child/contentPolicy.js

Index: lib/child/contentPolicy.js
===================================================================
--- a/lib/child/contentPolicy.js
+++ b/lib/child/contentPolicy.js
@@ -50,16 +50,43 @@ let collapsedClass = null;
 
 /**
  * Maps numerical content type IDs to strings.
  * @type Map.<number,string>
  */
 let types = new Map();
 
 /**
+ * Contains nodes stored by storeNodes() mapped by their IDs.
+ * @type Map.<string,DOMNode[]>
+ */
+let storedNodes = new Map();
+
+/**
+ * Process-dependent prefix to be used for unique nodes identifiers returned
+ * by storeNodes().
+ * @type string
+ */
+let nodesIDPrefix = Services.appinfo.processID + " ";
+
+/**
+ * Counter used to generate unique nodes identifiers in storeNodes().
+ * @type number
+ */
+let maxNodesID = 0;
+
+addMessageListener("AdblockPlus:DeleteNodes", onDeleteNodes);
+addMessageListener("AdblockPlus:RefilterNodes", onRefilterNodes);
+
+onShutdown.add(() => {
+  removeMessageListener("AdblockPlus:DeleteNodes", onDeleteNodes);
+  removeMessageListener("AdblockPlus:RefilterNodes", onRefilterNodes);
+});
+
+/**
  * Checks whether a request should be allowed, hides it if necessary
  * @param wnd {nsIDOMWindow}
  * @param node {nsIDOMElement}
  * @param contentType {String}
  * @param location {String} location of the request, filter key if contentType is ELEMHIDE
  * @param [callback] {Function} If present, the request will be sent
  *                              asynchronously and callback called with the
  *                              response
@@ -113,16 +140,73 @@ let shouldAllow = exports.shouldAllow = 
       callback(processResponse(data));
     });
   }
   else
     return processResponse(sendSyncMessage("AdblockPlus:ShouldAllow", data));
 };
 
 /**
+ * Stores nodes and generates a unique ID for them that can be used for
+ * Policy.refilterNodes() later. It's important that Policy.deleteNodes() is
+ * called later, otherwise the nodes will be leaked.
+ * @param {DOMNode[]} nodes  list of nodes to be stored
+ * @return {string}  unique ID for the nodes
+ */
+let storeNodes = exports.storeNodes = function(nodes)
+{
+  let id = nodesIDPrefix + (++maxNodesID);
+  storedNodes.set(id, nodes);
+  return id;
+};
+
+/**
+ * Called via message whenever Policy.deleteNodes() is called in the parent.
+ */
+function onDeleteNodes(message)
+{
+  storedNodes.delete(message.data);
+}
+
+/**
+ * Called via message whenever Policy.refilterNodes() is called in the parent.
+ */
+function onRefilterNodes(message)
+{
+  let {nodesID, entry} = message.data;
+  let nodes = storedNodes.get(nodesID);
+  if (nodes)
+    for (let node of nodes)
+      if (node.nodeType == Ci.nsIDOMNode.ELEMENT_NODE)
+        Utils.runAsync(refilterNode.bind(this, node, entry));
+}
+
+/**
+ * Re-checks filters on an element.
+ */
+function refilterNode(/**Node*/ node, /**Object*/ entry)
+{
+  let wnd = Utils.getWindow(node);
+  if (!wnd || wnd.closed)
+    return;
+
+  if (entry.type == "OBJECT")
+  {
+    node.removeEventListener("mouseover", objectMouseEventHander, true);
+    node.removeEventListener("mouseout", objectMouseEventHander, true);
+  }
+
+  shouldAllow(wnd, node, entry.type, entry.location, (allow) => {
+    // Force node to be collapsed
+    if (!allow)
+      schedulePostProcess(node)
+  });
+}
+
+/**
  * Actual nsIContentPolicy and nsIChannelEventSink implementation
  * @class
  */
 var PolicyImplementation =
 {
   classDescription: "Adblock Plus content policy",
   classID: Components.ID("cfeaabe6-1dd1-11b2-a0c6-cb5c268894c9"),
   contractID: "@adblockplus.org/abp/policy;1",