Issue 3654 - Reuse splitSelector() from cssProperties.js

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 @@
           stylesheet.addRule(selector, "display: none !important;");
         }
       }
     );
   });
 
   observer.observe(style.parentNode, {childList: true});
   return observer;
 }
 
-function convertSelectorsForShadowDOM(selectors)
-{
-  var result = [];
-  var prefix = "::content ";
-
-  for (var i = 0; i < selectors.length; i++)
-  {
-    var selector = selectors[i];
-    if (selector.indexOf(",") == -1)
-    {
-      result.push(prefix + selector);
-      continue;
-    }
-
-    var start = 0;
-    var sep = "";
-    for (var j = 0; j < selector.length; j++)
-    {
-      var chr = selector[j];
-      if (chr == "\\")
-        j++;
-      else if (chr == sep)
-        sep = "";
-      else if (sep == "")
-      {
-        if (chr == '"' || chr == "'")
-          sep = chr;
-        else if (chr == ",")
-        {
-          result.push(prefix + selector.substring(start, j));
-          start = j + 1;
-        }
-      }
-    }
-
-    result.push(prefix + selector.substring(start));
-  }
-
-  return result;
-}
-
 function init(document)
 {
   var shadow = null;
   var style = null;
   var observer = null;
   var tracer = null;
   var propertyFilters = new CSSPropertyFilters(window, addElemHideSelectors);
 
   // Use Shadow DOM if available to don't mess with web pages that rely on
   // the order of their own <style> tags (#309).
@@ skipping 30 matching lines @@
       if (!style.sheet)
         return;
 
       observer = reinjectRulesWhenRemoved(document, style);
     }
 
     // If using shadow DOM, we have to add the ::content pseudo-element
     // before each selector, in order to match elements within the
     // insertion point.
     if (shadow)
-      selectors = convertSelectorsForShadowDOM(selectors);
+    {
+      var preparedSelectors = [];
+      for (var i = 0; i < selectors.length; i++)
+      {
+        var subSelectors = splitSelector(selectors[i]);
+        for (var j = 0; j < subSelectors.length; j++)
+          preparedSelectors.push("::content " + subSelectors[j]);
+      }
+      selectors = preparedSelectors;

[Sebastian Noack, 2016/02/15 17:48:31]

For reference, I initially tried to modify the selectors array inline using
splice, instead creating a new array, while getting rid of
convertSelectorsForShadowDOM(). This however, made the whole function more 10
times slower.

+    }
 
     // WebKit (and Blink?) apparently chokes when the selector list in a
     // CSS rule is huge. So we split the elemhide selectors into groups.
     while (selectors.length > 0)
     {
       var selector = selectors.splice(0, SELECTOR_GROUP_SIZE).join(", ");
       style.sheet.addRule(selector, "display: none !important;");
     }
   };
 
@@ skipping 83 matching lines @@
   }, true);
 
   return updateStylesheet;
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   window.updateStylesheet = init(document);
 }