Bug 350949. Feed preview leaks memory. Check for multiple list members after frantic reloading. r=mano

browser/components/feeds/src/FeedConverter.js

@@ -425,16 +425,20 @@ var FeedResultService = {
   removeFeedResult: function FRS_removeFeedResult(uri) {
     NS_ASSERT(uri != null, "null URI!");
     var resultList = this._results[uri.spec];
+    if (!resultList)
+      return;
+    var deletions = 0;
     for (var i = 0; i < resultList.length; ++i) {
       if (resultList[i].uri == uri) {
         delete resultList[i];
-        // send the null value to the end of our little list and pop
-        // it off
-        resultList.sort(); 
-        resultList.pop();
-        break;
+        ++deletions;
       }
     }
+    
+    // send the holes to the end
+    resultList.sort();
+    // and trim the list
+    resultList.splice(resultList.length - deletions, deletions);
     if (resultList.length == 0)
       delete this._results[uri.spec];
   },

browser/components/feeds/src/FeedWriter.js

@@ -695,13 +695,14 @@ FeedWriter.prototype = {
   
   _window: null,
   _document: null,
-  
+  _feedURI: null,
+
   /**
    * See nsIFeedWriter
    */
   write: function FW_write(window) {
-    var originalURI = this._getOriginalURI(window);
-    if (!originalURI)
+    this._feedURI = this._getOriginalURI(window);
+    if (!this._feedURI)
       return;
     try {
       this._window = window;
@@ -731,10 +732,7 @@ FeedWriter.prototype = {
       this._writeFeedContent(container);
     }
     finally {
-      var feedService = 
-          Cc["@mozilla.org/browser/feeds/result-service;1"].
-          getService(Ci.nsIFeedResultService);
-      feedService.removeFeedResult(originalURI);
+      this._removeFeedFromCache();
     }
   },
 
@@ -751,6 +749,17 @@ FeedWriter.prototype = {
     prefs.removeObserver(PREF_SELECTED_READER, this);
     prefs.removeObserver(PREF_SELECTED_WEB, this);
     prefs.removeObserver(PREF_SELECTED_APP, this);
+    this._removeFeedFromCache();
+  },
+
+  _removeFeedFromCache: function FW__removeFeedFromCache() {
+    if (this._feedURI) {
+      var feedService = 
+           Cc["@mozilla.org/browser/feeds/result-service;1"].
+           getService(Ci.nsIFeedResultService);
+      feedService.removeFeedResult(this._feedURI);
+      this._feedURI = null;
+    }
   },
 
   /**