Issue 1802 - Fix element hiding filters with multiple CSS selectors when using shadow DOM

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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 148 matching lines @@
 
   for (var i = 0; i < selectors.length; i++)
   {
     var selector = selectors[i];
     var start = 0;
     var sep = "";
 
     for (var j = 0; j < selector.length; j++)
     {
       var chr = selector[j];
-      switch (chr)
-      {
-        case "\\":
-          j++;
-          break;
-        case sep:
-          sep = "";
-          break;
-        case '"':
-        case "'":
-          sep = chr;
-          break;

[Wladimir Palant, 2015/01/22 08:15:52]

Note that technically there might be more separators: ( expects ), [ expects ].
However, I didn't find a scenario where an unescaped comma would be valid inside
parentheses, and that would also complicate things given that there could be
quoted strings inside.

-        case ",":
-          if (sep == "")
-          {
-            result.push(prefix + selector.substring(start, j));
-            start = j + 1;
-          }

[Wladimir Palant, 2015/01/22 08:15:52]

Nit: please add a break statement here, for consistency. Otherwise, if somebody
adds a new case statement they will need to remember doing that - and typically
people won't notice a missing break statement.

[Sebastian Noack, 2015/01/22 09:40:59]

Ah, let's go with if/else then. It's more compact, and seems to perform exactly
the same on Chrome.

-      }
-    }
-
-    result.push(prefix + selector.substring(start, j));

[Wladimir Palant, 2015/01/22 08:15:52]

The second parameter is unnecessary here, can be simply
selector.substring(start). Then you won't need to use the loop variable outside
the loop.

[Sebastian Noack, 2015/01/22 09:40:59]

Oh, you are right.

+      if (chr == "\\")
+        j++;
+      else if (chr == sep)
+        sep = "";
+      else if (chr == '"' || chr == "'")
+        sep = chr;
+      else if (chr == "," && sep == "")
+      {
+        result.push(prefix + selector.substring(start, j));
+        start = j + 1;
+      }
+    }
+
+    result.push(prefix + selector.substring(start));
   }
 
   return result;
 }
 
 function init(document)
 {
   // Use Shadow DOM if available to don't mess with web pages that rely on
   // the order of their own <style> tags (#309).
   //
@@ skipping 80 matching lines @@
   }, true);
 
   ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   init(document);
 }