Issue 5587, 5748 - Use mobile options page on Firefox for Android

ext/background.js

Index: ext/background.js
===================================================================
--- a/ext/background.js
+++ b/ext/background.js
@@ -312,26 +312,16 @@
   chrome.tabs.onActivated.addListener(details =>
   {
     ext.pages.onActivated._dispatch(new Page({id: details.tabId}));
   });
 
 
   /* Browser actions */
 
-  // On Firefox for Android, open the options page directly when the browser
-  // action is clicked.
-  if (!("getPopup" in chrome.browserAction))
-  {
-    chrome.browserAction.onClicked.addListener(() =>
-    {
-      ext.showOptions();
-    });
-  }
-
   let BrowserAction = function(tabId)
   {
     this._tabId = tabId;
     this._changes = null;
   };
   BrowserAction.prototype = {
     _applyChanges()
     {
@@ -731,39 +721,38 @@
           });
         });
       }
     }
     else if ("windows" in chrome)
     {
       // Edge does not yet support runtime.openOptionsPage (tested version 38)
       // and so this workaround needs to stay for now.
-      // We are not using extension.getURL to get the absolute path here
-      // because of the Edge issue:
-      // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10276332/
       let optionsUrl = "options.html";
-      let fullOptionsUrl = ext.getURL(optionsUrl);
 
       chrome.tabs.query({}, tabs =>
       {
         // We find a tab ourselves because Edge has a bug when quering tabs
         // with extension URL protocol:
         // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8094141/ 
         // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8604703/
+        let fullOptionsUrl = ext.getURL(optionsUrl);
         let tab = tabs.find(element => element.url == fullOptionsUrl);
         if (tab)
         {
           chrome.windows.update(tab.windowId, {focused: true});
           chrome.tabs.update(tab.id, {active: true});
 
           if (callback)
             callback(new Page(tab));
         }
         else
         {
+          // We don't use fullOptionsUrl here because of this Edge issue:
+          // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10276332
           ext.pages.open(optionsUrl, callback);
         }
       });
     }
     else
     {
       // Firefox for Android before version 57 does not support
       // runtime.openOptionsPage, nor does it support the windows API. Since