Issue 3654 - Properly split up selectors when applying CSS property filters

chrome/content/cssProperties.js

+function splitSelector(selector)

[Sebastian Noack, 2016/02/15 17:19:08]

This logic has been copied (with some minor changes) from
adblockpluschrome/include.perload.js. After the dependency update we should
reuse splitSelector() there.

[kzar, 2016/02/15 17:30:14]

Acknowledged. (Mind filing an issue for that?)

[Sebastian Noack, 2016/02/15 17:49:31]

I attached the patch the same issue:
https://codereview.adblockplus.org/29336409/

+{
+  if (selector.indexOf(",") == -1)
+    return [selector];
+
+  var selectors = [];
+  var start = 0;
+  var level = 0;
+  var sep = "";
+
+  for (var i = 0; i < selector.length; i++)
+  {
+    var chr = selector[i];
+
+    if (chr == "\\")        // ignore escaped characters
+      i++;
+    else if (chr == sep)    // don't split within quoted text
+      sep = "";             // e.g. [attr=","]
+    else if (sep == "")
+    {
+      if (chr == '"' || chr == "'")
+        sep = chr;
+      else if (chr == "(")  // don't split between parentheses
+        level++;            // e.g. :matches(div,span)
+      else if (chr == ")")
+        level = Math.max(0, level - 1);
+      else if (chr == "," && level == 0)
+      {
+        selectors.push(selector.substring(start, i));
+        start = i + 1;
+      }
+    }
+  }
+
+  selectors.push(selector.substring(start));
+  return selectors;
+}
+
 function CSSPropertyFilters(window, addSelectorsFunc) {
   this.window = window;
   this.addSelectorsFunc = addSelectorsFunc;
 }
-
 CSSPropertyFilters.prototype = {
   stringifyStyle: function(style)
   {
     var styles = [];
     for (var i = 0; i < style.length; i++)
     {
       var property = style.item(i);
       var value    = style.getPropertyValue(property);
       var priority = style.getPropertyPriority(property);
       styles.push(property + ": " + value + (priority ? " !" + priority : "") + ";");
@@ skipping 17 matching lines @@
       var style = this.stringifyStyle(rule.style);
       for (var j = 0; j < this.patterns.length; j++)
       {
         var pattern = this.patterns[j];
         var regexp = pattern.regexp;
 
         if (typeof regexp == "string")
           regexp = pattern.regexp = new RegExp(regexp);
 
         if (regexp.test(style))
-          selectors.push(pattern.prefix + rule.selectorText + pattern.suffix);
+        {
+          var subSelectors = splitSelector(rule.selectorText);
+          for (var k = 0; k < subSelectors.length; k++)
+            selectors.push(pattern.prefix + subSelectors[k] + pattern.suffix);
+        }
       }
     }
   },
 
   addSelectors: function(stylesheets)
   {
     var selectors = [];
     for (var i = 0; i < stylesheets.length; i++)
       this.findSelectors(stylesheets[i], selectors);
     this.addSelectorsFunc(selectors);
@@ skipping 24 matching lines @@
   apply: function()
   {
     if (this.patterns.length > 0)
     {
       var document = this.window.document;
       this.addSelectors(document.styleSheets);
       document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 };