Slight improvements to URL Fixer code

chrome/content/options.js

Index: chrome/content/options.js
===================================================================
--- a/chrome/content/options.js
+++ b/chrome/content/options.js
@@ -32,50 +32,44 @@ function onFindChange()
 function onPrefChange(name)
 {
   if (name == "custom_replace" || name == "whitelist")
     updateList();
 }
 
 function updateList()
 {
+  //
+  // Custom rules
+  //
+
   let ruleListElement = E("custom_corrections");
-  let whitelistElement = E("whitelist");
 
   // Remove existing list entries
   for (let i = ruleListElement.getRowCount() - 1; i >= 0; i--)
     ruleListElement.removeItemAt(i);
-  for (let i = whitelistElement.getRowCount() - 1; i >= 0; i--)
-    whitelistElement.removeItemAt(i);
 
   // Build a list of custom rules and sort it alphabetically
   let prefRulesList = Prefs.custom_replace;
-  let prefWhitelist = Prefs.whitelist;
   let ruleList = [];
-  let whitelist = [];
-  
+
   for (let searchString in prefRulesList)
   {
     ruleList.push([searchString, prefRulesList[searchString]]);
   }
-  for (let searchString in prefWhitelist)
-  {
-    whitelist.push(searchString);
-  }
 
   ruleList.sort(function(a, b)
   {
     if (a[0] < b[0])
       return -1;
     else if (a[0] > b[0])
       return 1;
     else
       return 0;
   });
-  whitelist.sort();
 
   // Add the rules to the list
   if (ruleList.length > 0)
   {
     for (let i = 0; i < ruleList.length; i++)
     {
       let [searchString, replacement] = ruleList[i];
 
@@ -97,23 +91,38 @@ function updateList()
   {
     let option = document.createElement("listitem");
     option.setAttribute("class", "auto-entry");
     option.setAttribute("label", ruleListElement.getAttribute("_emptyLabel"));
 
     ruleListElement.appendChild(option);
   }
 
+  //
+  // Exception rules
+  //
+
+  let whitelistElement = E("whitelist");
+
+  // Remove existing list entries
+  for (let i = whitelistElement.getRowCount() - 1; i >= 0; i--)
+    whitelistElement.removeItemAt(i);
+
+  // Build a list of exceptions and sort it alphabetically
+  let whitelist = Object.keys(Prefs.whitelist);
+  whitelist.sort();
+
+  // Add the rules to the list
   if (whitelist.length > 0)
   {
     for (let i = 0; i < whitelist.length; i++)
     {
       let option = document.createElement("listitem");
       option.setAttribute("value", whitelist[i]);
-      option.setAttribute("label", whitelist[i])
+      option.setAttribute("label", whitelist[i]);
 
       whitelistElement.appendChild(option);
     }
   }
   else
   {
     let option = document.createElement("listitem");
     option.setAttribute("class", "auto-entry");