Issue 6868 - Enable capturing of surrounding wildcards for rewrite filters

lib/common.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 14 matching lines @@
 function textToRegExp(text)
 {
   return text.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
 }
 
 exports.textToRegExp = textToRegExp;
 
 /**
  * Converts filter text into regular expression string
  * @param {string} text as in Filter()
+ * @param {boolean} [captureAll=false] whether to enable the capturing of
+ *   leading and trailing wildcards in the filter text; by default, leading and
+ *   trailing wildcards are stripped out
  * @return {string} regular expression representation of filter text
  */
-function filterToRegExp(text)
+function filterToRegExp(text, captureAll = false)
 {
+  // remove multiple wildcards
+  text = text.replace(/\*+/g, "*");
+
+  if (!captureAll)
+  {
+    // remove leading wildcard
+    if (text[0] == "*")
+      text = text.substring(1);
+
+    // remove trailing wildcard
+    if (text[text.length - 1] == "*")
+      text = text.substring(0, text.length - 1);
+  }
+
   return text
-    // remove multiple wildcards
-    .replace(/\*+/g, "*")
     // remove anchors following separator placeholder
     .replace(/\^\|$/, "^")
     // escape special symbols
     .replace(/\W/g, "\\$&")
     // replace wildcards by .*
     .replace(/\\\*/g, ".*")
     // process separator placeholders (all ANSI characters but alphanumeric
     // characters and _%.-)
     .replace(/\\\^/g, "(?:[\\x00-\\x24\\x26-\\x2C\\x2F\\x3A-\\x40\\x5B-\\x5E\\x60\\x7B-\\x7F]|$)")
     // process extended anchor at expression start
     .replace(/^\\\|\\\|/, "^[\\w\\-]+:\\/+(?!\\/)(?:[^\\/]+\\.)?")
     // process anchor at expression start
     .replace(/^\\\|/, "^")
     // process anchor at expression end
-    .replace(/\\\|$/, "$")
-    // remove leading wildcards
-    .replace(/^(\.\*)/, "")
-    // remove trailing wildcards
-    .replace(/(\.\*)$/, "");
+    .replace(/\\\|$/, "$");
 }
 
 exports.filterToRegExp = filterToRegExp;
 
 function splitSelector(selector)
 {
   if (!selector.includes(","))
     return [selector];
 
   let selectors = [];
@@ skipping 125 matching lines @@
     // Note that the first group in the regular expression is optional. If it
     // doesn't match (e.g. "#foo::nth-child(1)"), type will be an empty string.
     qualifiedSelector += sub.substr(0, index) + type + qualifier + rest;
   }
 
   // Remove the initial comma and space.
   return qualifiedSelector.substr(2);
 }
 
 exports.qualifySelector = qualifySelector;