Issue 5339 - Properly select element for pseudo-element

chrome/content/elemHideEmulation.js

Index: chrome/content/elemHideEmulation.js
===================================================================
--- a/chrome/content/elemHideEmulation.js
+++ b/chrome/content/elemHideEmulation.js
@@ -250,40 +250,52 @@
         prefix + "*" : prefix;
     let elements = subtree.querySelectorAll(actualPrefix);
     for (let element of elements)
       if (element.textContent.includes(this._text))
         yield element;
   }
 };
 
-function PropsSelector(propertyExpression)
+function PropsSelector(propertyExpression, pseudoElem)
 {
   let regexpString;
   if (propertyExpression.length >= 2 && propertyExpression[0] == "/" &&
       propertyExpression[propertyExpression.length - 1] == "/")
   {
     regexpString = propertyExpression.slice(1, -1)
       .replace("\\x7B ", "{").replace("\\x7D ", "}");
   }
   else
     regexpString = filterToRegExp(propertyExpression);
 
   this._regexp = new RegExp(regexpString, "i");
+  this._pseudoElem = pseudoElem || "";
 }
 
 PropsSelector.prototype = {
   preferHideWithSelector: true,
 
   *findPropsSelectors(styles, prefix, regexp)
   {
     for (let style of styles)
       if (regexp.test(style.style))
         for (let subSelector of style.subSelectors)
+        {
+          if (this._pseudoElem)
+          {
+            let idx = subSelector.lastIndexOf(this._pseudoElem);
+            if (idx != subSelector.length - this._pseudoElem.length)
+              continue;
+            if (idx > 0 && subSelector[idx - 1] == ":")
+              idx--;
+            subSelector = subSelector.substring(0, idx);
+          }
           yield prefix + subSelector;
+        }
   },
 
   *getSelectors(prefix, subtree, styles)
   {
     for (let selector of this.findPropsSelectors(styles, prefix, this._regexp))
       yield [selector, subtree];
   }
 };
@@ -336,16 +348,20 @@
       this.window.console.error(
         new SyntaxError("Failed to parse Adblock Plus " +
                         `selector ${selector} ` +
                         "due to unmatched parentheses."));
       return null;
     }
     if (match[1] == "properties")
       selectors.push(new PropsSelector(content.text));
+    else if (match[1] == "properties-before")
+      selectors.push(new PropsSelector(content.text, ":before"));
+    else if (match[1] == "properties-after")
+      selectors.push(new PropsSelector(content.text, ":after"));
     else if (match[1] == "has")
     {
       let hasSelectors = this.parseSelector(content.text);
       if (hasSelectors == null)
         return null;
       selectors.push(new HasSelector(hasSelectors));
     }
     else if (match[1] == "contains")