Issue 705 - Generate element hiding instead request blocking filters for non-HTTP URLs

include.postload.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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 363 matching lines @@
 
   clickHideFilters = new Array();
   selectorList = new Array();
 
   var addSelector = function(selector)
   {
     clickHideFilters.push(document.domain + "##" + selector);
     selectorList.push(selector);
   };
 
+  var addSelectorFromAttribute = function(element, attribute)
+  {
+    var value = element.getAttribute(attribute);
+    if (value)
+      addSelector(element.localName + "[" + attribute + '="' + value.replace(/"/g, '\\"') + '"]');

[Wladimir Palant, 2014/10/24 17:56:55]

This isn't a sufficient escaping approach. First of all, the attribute name
should be escaped as well. Here the corresponding code from Element Hiding
Helper:

function escapeChar(dummy, match)
{
  return "\\" + match.charCodeAt(0).toString(16) + " ";
}

function escapeName(name)
{
  return name.replace(/([^\w\-])/g, "\\$1")
             .replace(/\\([\{\}])/g, escapeChar);
}

The rules for escaping values are even more complicated, e.g. one has to make
sure to escape backslashes. Again, code from Element Hiding Helper:

var escapedValue = attr.selected.replace(/(["\\])/g, '\\$1')
                                .replace(/([\{\}])/g, escapeChar)
                                .replace(/([^\S ])/g, escapeChar);

Frankly, I no longer remember why all of this was necessary. We had lots of
issues with this code and had to adjust it multiple times - we would need to
look at the change history if we want to know the details.

Not that any other selectors the existing code proposes are properly escaped...

[Sebastian Noack, 2014/10/30 16:36:24]

The attribute name is hard-coded in the calling code and needs no escaping. I
restructured the code to make it more obvious.
Backslashes are escaped now. However, I tested it and there is no need to escape
curly brackets and any kind of whitespaces on Chrome and Safari.

+  };
+
   if (elementId)
     addSelector("#" + elementId);
 
   if (elementClasses && elementClasses.length > 0)
   {
     var selector = "";
 
     for (var i = 0; i < elt.classList.length; i++)
       selector += "." + elt.classList[i].replace(/([^\w-])/, "\\$1");
 
     addSelector(selector);
   }
 
   if (url)
   {
-    clickHideFilters.push(url.replace(/^[\w\-]+:\/+(?:www\.)?/, "||"));
-    selectorList.push('[src="' + elt.getAttribute("src") + '"]');
+    if (/^https?:/i.test(url))
+    {
+      clickHideFilters.push(url.replace(/^[\w\-]+:\/+(?:www\.)?/, "||"));
+      selectorList.push('[src="' + elt.getAttribute("src") + '"]');
+    }
+    else
+      addSelectorFromAttribute(elt, "src");
   }
 
   // Show popup
   clickHide_showDialog(e.clientX, e.clientY, clickHideFilters);
 
   // restore the original style, before generating the fallback filter that
   // will include the style, and to prevent highlightElements from saving those
   unhighlightElement(currentElement);
 
   // as last resort, create a filter based on inline styles
-  if (clickHideFilters.length == 0 && elt.hasAttribute("style"))
-    addSelector(elt.localName + '[style="' + elt.getAttribute("style").replace(/"/g, '\\"') + '"]');
+  if (clickHideFilters.length == 0)
+    addSelectorFromAttribute(elt, "style");
 
   // Highlight the elements specified by selector in yellow
   highlightElements(selectorList.join(","));
   // Now, actually highlight the element the user clicked on in red
   highlightElement(currentElement, "#fd1708", "#f6a1b5");
 
   // Make sure the browser doesn't handle this click
   e.preventDefault();
   e.stopPropagation();
 }
@@ skipping 211 matching lines @@
         break;
       default:
         sendResponse({});
         break;
     }
   });
 
   if (window == window.top)
     ext.backgroundPage.sendMessage({type: "report-html-page"});
 }