Issue 6619 - Qualify CSS selectors in document style sheet correctly

lib/content/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 159 matching lines @@
   }
   return all ? subtree.querySelectorAll(selector) :
     subtree.querySelector(selector);
 }
 
 function scopedQuerySelectorAll(subtree, selector)
 {
   return scopedQuerySelector(subtree, selector, true);
 }
 
-const regexpRegexp = /^\/(.*)\/([im]*)$/;
+const regexpRegexp = /^\/(.*)\/([imu]*)$/;
 
 /**
  * Make a regular expression from a text argument. If it can be parsed as a
  * regular expression, parse it and the flags.
  * @param {string} text the text argument.
  * @return {?RegExp} a RegExp object or null in case of error.
  */
 function makeRegExpParameter(text)
 {
   let [, pattern, flags] =
@@ skipping 27 matching lines @@
   // Just in case the getSelectors() generator above had to run some heavy
   // document.querySelectorAll() call which didn't produce any results, make
   // sure there is at least one point where execution can pause.
   yield null;
 }
 
 function PlainSelector(selector)
 {
   this._selector = selector;
   this.maybeDependsOnAttributes = /[#.]|\[.+\]/.test(selector);
+  this.dependsOnDOM = this.maybeDependsOnAttributes;
 }
 
 PlainSelector.prototype = {
   /**
    * Generator function returning a pair of selector
    * string and subtree.
    * @param {string} prefix the prefix for the selector.
    * @param {Node} subtree the subtree we work on.
    * @param {StringifiedStyle[]} styles the stringified style objects.
    */
   *getSelectors(prefix, subtree, styles)
   {
     yield [prefix + this._selector, subtree];
   }
 };
 
 const incompletePrefixRegexp = /[\s>+~]$/;
 
 function HasSelector(selectors)
 {
   this._innerSelectors = selectors;
 }
 
 HasSelector.prototype = {
-  requiresHiding: true,
   dependsOnDOM: true,
 
   get dependsOnStyles()
   {
     return this._innerSelectors.some(selector => selector.dependsOnStyles);
   },
 
   get dependsOnCharacterData()
   {
     return this._innerSelectors.some(
@@ skipping 42 matching lines @@
     }
   }
 };
 
 function ContainsSelector(textContent)
 {
   this._regexp = makeRegExpParameter(textContent);
 }
 
 ContainsSelector.prototype = {
-  requiresHiding: true,
   dependsOnDOM: true,
   dependsOnCharacterData: true,
 
   *getSelectors(prefix, subtree, styles)
   {
     for (let element of this.getElements(prefix, subtree, styles))
       yield [makeSelector(element), subtree];
   },
 
   *getElements(prefix, subtree, styles)
@@ skipping 37 matching lines @@
     regexpString = propertyExpression.slice(1, -1)
       .replace("\\7B ", "{").replace("\\7D ", "}");
   }
   else
     regexpString = filterToRegExp(propertyExpression);
 
   this._regexp = new RegExp(regexpString, "i");
 }
 
 PropsSelector.prototype = {
-  preferHideWithSelector: true,
   dependsOnStyles: true,
 
   *findPropsSelectors(styles, prefix, regexp)
   {
     for (let style of styles)
       if (regexp.test(style.style))
         for (let subSelector of style.subSelectors)
         {
           if (subSelector.startsWith("*") &&
               !incompletePrefixRegexp.test(prefix))
@@ skipping 14 matching lines @@
   }
 };
 
 function Pattern(selectors, text)
 {
   this.selectors = selectors;
   this.text = text;
 }
 
 Pattern.prototype = {
-  isSelectorHidingOnlyPattern()
-  {
-    return getCachedPropertyValue(
-      this, "_selectorHidingOnlyPattern",
-      () => this.selectors.some(selector => selector.preferHideWithSelector) &&
-            !this.selectors.some(selector => selector.requiresHiding)
-    );
-  },
-
   get dependsOnStyles()
   {
     return getCachedPropertyValue(
       this, "_dependsOnStyles",
       () => this.selectors.some(selector => selector.dependsOnStyles)
     );
   },
 
   get dependsOnDOM()
   {
@@ skipping 30 matching lines @@
   },
 
   get dependsOnCharacterData()
   {
     // Observe changes to character data only if there's a contains selector in
     // one of the patterns.
     return getCachedPropertyValue(
       this, "_dependsOnCharacterData",
       () => this.selectors.some(selector => selector.dependsOnCharacterData)
     );
+  },
+
+  matchesMutationTypes(mutationTypes)
+  {
+    let mutationTypeMatchMap = getCachedPropertyValue(
+      this, "_mutationTypeMatchMap",
+      () => new Map([
+        // All types of DOM-dependent patterns are affected by mutations of
+        // type "childList".
+        ["childList", true],
+        ["attributes", this.maybeDependsOnAttributes],
+        ["characterData", this.dependsOnCharacterData]
+      ])
+    );
+
+    for (let mutationType of mutationTypes)
+    {
+      if (mutationTypeMatchMap.get(mutationType))
+        return true;
+    }
+
+    return false;
   }
 };
+
+function extractMutationTypes(mutations)
+{
+  let types = new Set();
+
+  for (let mutation of mutations)
+  {
+    types.add(mutation.type);
+
+    // There are only 3 types of mutations: "attributes", "characterData", and
+    // "childList".
+    if (types.size == 3)
+      break;
+  }
+
+  return types;
+}
 
 function filterPatterns(patterns, {stylesheets, mutations})
 {
   if (!stylesheets && !mutations)
     return patterns.slice();
 
+  let mutationTypes = mutations ? extractMutationTypes(mutations) : null;
+
   return patterns.filter(
     pattern => (stylesheets && pattern.dependsOnStyles) ||
-               (mutations && pattern.dependsOnDOM)
+               (mutations && pattern.dependsOnDOM &&
+                pattern.matchesMutationTypes(mutationTypes))
   );
 }
 
 function shouldObserveAttributes(patterns)
 {
   return patterns.some(pattern => pattern.maybeDependsOnAttributes);
 }
 
 function shouldObserveCharacterData(patterns)
 {
@@ skipping 182 matching lines @@
 
         pattern = patterns.shift();
 
         generator = evaluate(pattern.selectors, 0, "",
                              this.document, cssStyles);
       }
       for (let selector of generator)
       {
         if (selector != null)
         {
-          if (!this.useInlineStyles ||
-              pattern.isSelectorHidingOnlyPattern())
+          if (!this.useInlineStyles)
           {
             selectors.push(selector);
             selectorFilters.push(pattern.text);
           }
           else
           {
             for (let element of this.document.querySelectorAll(selector))
             {
               elements.push(element);
               elementFilters.push(pattern.text);
@@ skipping 144 matching lines @@
           characterData: shouldObserveCharacterData(this.patterns),
           subtree: true
         }
       );
       this.document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 };
 
 exports.ElemHideEmulation = ElemHideEmulation;