Issue 5864 - Remove previous style sheet before adding one

lib/cssInjection.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 25 matching lines @@
     code: styleSheet,
     cssOrigin: "user",
     frameId,
     matchAboutBlank: true,
     runAt: "document_start"
   });
 }
 
 function removeStyleSheet(tabId, frameId, styleSheet)
 {
-  chrome.tabs.removeCSS(tabId, {

[kzar, 2018/01/24 14:30:53]

Should be `browser.tabs.removeCSS`? I guess we also need to check the API exists
and add it to the webextension pollyfills?

[Manish Jethani, 2018/01/24 16:37:44]

Yes, sorry this patch is really old.

Done.

(We don't have to check for this API since the code will never get there if
userStyleSheetsSupported is false.)

+  browser.tabs.removeCSS(tabId, {
     code: styleSheet,
     cssOrigin: "user",
     frameId,
     matchAboutBlank: true
   });
 }
 
-function updateFrameStyles(pageId, frameId, selectors, groupName)

[kzar, 2018/01/24 14:30:53]

I think `pageId` should be `tabId`, though you refer to both below.

[Manish Jethani, 2018/01/24 16:37:44]

Fixed.

+function updateFrameStyles(tabId, frameId, selectors, groupName)
 {
   let styleSheet = null;
   if (selectors.length > 0)
     styleSheet = selectors.join(", ") + "{display: none !important;}";
 
-  let frame = ext.getFrame(pageId, frameId);
+  let frame = ext.getFrame(tabId, frameId);
   if (!frame.injectedStyleSheets)
     frame.injectedStyleSheets = new Map();
 
   let oldStyleSheet = frame.injectedStyleSheets.get(groupName);
 
   // Ideally we would compare the old and new style sheets and skip this code
   // if they're the same, but the old style sheet can be a leftover from a
   // previous instance of the frame. We must add the new style sheet
   // regardless.
 
   // Add the new style sheet first to keep previously hidden elements from
   // reappearing momentarily.
   if (styleSheet)
     addStyleSheet(tabId, frameId, styleSheet);
 
   // Sometimes the old and new style sheets can be exactly the same. In such a
   // case, do not remove the "old" style sheet, because it is in fact the new
   // style sheet now.
   if (oldStyleSheet && oldStyleSheet != styleSheet)
     removeStyleSheet(tabId, frameId, oldStyleSheet);
+
   frame.injectedStyleSheets.set(groupName, styleSheet);
 }
 
 port.on("elemhide.getSelectors", (message, sender) =>
 {
   let selectors = [];
   let emulatedPatterns = [];
   let trace = devtools && devtools.hasPanel(sender.page);
   let inline = !userStyleSheetsSupported;
 
@@ skipping 22 matching lines @@
     response.selectors = selectors;
 
   return response;
 });
 
 port.on("elemhide.injectSelectors", (message, sender) =>
 {
   updateFrameStyles(sender.page.id, sender.frame.id, message.selectors,
                     message.groupName);
 });