Issue 5436 - Allow relative selectors in :-abp-has()

chrome/content/elemHideEmulation.js

Index: chrome/content/elemHideEmulation.js
===================================================================
--- a/chrome/content/elemHideEmulation.js
+++ b/chrome/content/elemHideEmulation.js
@@ -184,16 +184,17 @@
    */
   *getSelectors(prefix, subtree, styles)
   {
     yield [prefix + this._selector, subtree];
   }
 };
 
 const incompletePrefixRegexp = /[\s>+~]$/;
+const relativeSelectorRegexp = /^[>+~]/;
 
 function HasSelector(selectors)
 {
   this._innerSelectors = selectors;
 }
 
 HasSelector.prototype = {
   requiresHiding: true,
@@ -219,18 +220,29 @@
   {
     let actualPrefix = (!prefix || incompletePrefixRegexp.test(prefix)) ?
         prefix + "*" : prefix;
     let elements = subtree.querySelectorAll(actualPrefix);
     for (let element of elements)
     {
       let iter = evaluate(this._innerSelectors, 0, "", element, styles);
       for (let selector of iter)
-        if (element.querySelector(selector))
-          yield element;
+      {
+        if (relativeSelectorRegexp.test(selector))
+          selector = ":scope" + selector;
+        try
+        {
+          if (element.querySelector(selector))
+            yield element;
+        }
+        catch (e)
+        {
+          // :scope isn't supported on Edge, ignore error caused by it.
+        }
+      }
     }
   }
 };
 
 function ContainsSelector(textContent)
 {
   this._text = textContent;
 }