Issue 5562 - Move Edge storage to IndexedDB

lib/io.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 12 matching lines @@
 {
   return keyPrefix + fileName;
 }
 
 function loadFile(fileName)
 {
   return new Promise((resolve, reject) =>
   {
     localforage.getItem(fileToKey(fileName), (err, value) =>
     {
-      if (err || !value)
+      if (err || value == null)
         reject({type: "NoSuchFile"});
       else
         resolve(value);
     });
   });
 }
 
 function saveFile(fileName, data)
 {
   let key = fileToKey(fileName);
@@ skipping 25 matching lines @@
    *    Name of the file to be read
    * @param {TextSink} listener
    *    Function that will be called for each line in the file
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   readFromFile(fileName, listener)
   {
     return loadFile(fileName).then(entry =>
     {
-      if ("content" in entry)
-      {
-        for (let line of entry.content)
-          listener(line);
-      }
+      for (let line of entry.content)
+        listener(line);
     });
   },
 
   /**
    * Writes text lines to a file.
    * @param {string} fileName
    *    Name of the file to be written
    * @param {Iterable.<string>} data
    *    An array-like or iterable object containing the lines (without line
    *    endings)
@@ skipping 65 matching lines @@
         lastModified: entry.lastModified
       };
     }).catch(error =>
     {
       if (error.type == "NoSuchFile")
         return {exists: false};
       throw error;
     });
   }
 };