Issue 6957 - Return common style sheet for unknown domains

lib/elemHide.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 80 matching lines @@
 let knownExceptionDomains = new Set();
 
 /**
  * Returns the suffix of the given domain that is known. If no suffix is known,
  * an empty string is returned.
  * @param {?string} domain
  * @returns {string}
  */
 function getKnownSuffix(domain)
 {
-  if (domain[domain.length - 1] == ".")
-    domain = domain.replace(/\.+$/, "");
-
-  domain = domain.toLowerCase();
-
   while (domain && !filtersByDomain.has(domain) &&
          !knownExceptionDomains.has(domain))
   {
     let index = domain.indexOf(".");
     domain = index == -1 ? "" : domain.substring(index + 1);
   }
 
   return domain;
 }
 
@@ skipping 24 matching lines @@
 function getUnconditionalSelectors()
 {
   if (!unconditionalSelectors)
     unconditionalSelectors = [...filterBySelector.keys()];
 
   return unconditionalSelectors;
 }
 
 /**
  * Returns the list of selectors that apply on a given domain from the subset
- * of filters that do not apply unconditionally on all domains. If no domain is
- * given, includes only selectors from generic filters.
- *
- * @param {string} [domain] The domain.
- * @param {boolean} [specificOnly=false] Whether selectors from generic filters
- *   should be included.
+ * of filters that do not apply unconditionally on all domains.
+ *
+ * @param {string} domain The domain.
+ * @param {boolean} specificOnly Whether selectors from generic filters should
+ *   be included.
  *
  * @returns {Array.<string>} The list of selectors.
  */
-function getConditionalSelectors(domain = "", specificOnly = false)
+function getConditionalSelectors(domain, specificOnly)
 {
   let selectors = [];
 
   let excluded = new Set();
   let currentDomain = domain;
 
   // This code is a performance hot-spot, which is why we've made certain
   // micro-optimisations. Please be careful before making changes.
   while (true)
   {
@@ skipping 45 matching lines @@
 
 /**
  * Returns the common style sheet that applies on all unknown domains.
  * @returns {string}
  */
 function getCommonStyleSheet()
 {
   if (!commonStyleSheet)
   {
     commonStyleSheet = getDefaultStyleSheet() +
-                       createStyleSheet(getConditionalSelectors());
+                       createStyleSheet(getConditionalSelectors("", false));
   }
 
   return commonStyleSheet;
 }
 
 ElemHideExceptions.on("added", ({domains, selector}) =>
 {
   commonStyleSheet = null;
 
   if (domains)
@@ skipping 127 matching lines @@
    *
    * @param {string} domain The domain.
    * @param {boolean} [specificOnly=false] Whether selectors from generic
    *   filters should be included.
    *
    * @returns {ElemHideStyleSheet} An object containing the CSS code and the
    *   list of selectors.
    */
   generateStyleSheetForDomain(domain, specificOnly = false)
   {
-    let knownSuffix = domain ? getKnownSuffix(domain) : "";
-
-    let selectors = getConditionalSelectors(knownSuffix, specificOnly);
-    let code = specificOnly ? createStyleSheet(selectors) :
-                 knownSuffix == "" ? getCommonStyleSheet() :
-                   (getDefaultStyleSheet() + createStyleSheet(selectors));
-
-    if (!specificOnly)
+    let code = null;
+    let selectors = null;
+
+    if (domain[domain.length - 1] == ".")
+      domain = domain.replace(/\.+$/, "");
+
+    domain = domain.toLowerCase();
+
+    if (specificOnly)
+    {
+      selectors = getConditionalSelectors(domain, true);
+      code = createStyleSheet(selectors);
+    }
+    else
+    {
+      let knownSuffix = getKnownSuffix(domain);
+
+      selectors = getConditionalSelectors(knownSuffix, false);
+      code = knownSuffix == "" ? getCommonStyleSheet() :
+               (getDefaultStyleSheet() + createStyleSheet(selectors));
+
       selectors = getUnconditionalSelectors().concat(selectors);
+    }
 
     return {code, selectors};
   }
 };
 
 /**
  * Splits a list of selectors into groups determined by the value of
  * <code>{@link selectorGroupSize}</code>.
  *
  * @param {Array.<string>} selectors
@@ skipping 43 matching lines @@
 {
   let styleSheet = "";
 
   for (let selectorGroup of splitSelectors(selectors))
     styleSheet += createRule(selectorGroup);
 
   return styleSheet;
 }
 
 exports.createStyleSheet = createStyleSheet;