Issue 7208 - Drop superfluous wildcards before processing pattern

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -683,21 +683,24 @@
  *   letters
  * @param {string} [domains]
  *   Domains that the filter is restricted to, e.g. "foo.com|bar.com|~baz.com"
  * @param {boolean} [thirdParty]
  *   Defines whether the filter should apply to third-party or first-party
  *   content only
  * @param {string} [sitekeys]
  *   Public keys of websites that this filter should apply to
+ * @param {?string} [rewrite]
+ *   The (optional) rule specifying how to rewrite the URL. See
+ *   BlockingFilter.prototype.rewrite.
  * @constructor
  * @augments ActiveFilter
  */
 function RegExpFilter(text, regexpSource, contentType, matchCase, domains,
-                      thirdParty, sitekeys)
+                      thirdParty, sitekeys, rewrite)
 {
   ActiveFilter.call(this, text, domains);
 
   if (contentType != null)
     this.contentType = contentType;
   if (matchCase)
     this.matchCase = matchCase;
   if (thirdParty != null)
@@ -712,16 +715,22 @@
     // The filter is a regular expression - convert it immediately to
     // catch syntax errors
     let regexp = new RegExp(regexpSource.substr(1, regexpSource.length - 2),
                             this.matchCase ? "" : "i");
     Object.defineProperty(this, "regexp", {value: regexp});
   }
   else
   {
+    // Patterns like /foo/bar/* exist so that they are not treated as regular
+    // expressions. We drop any superfluous wildcards here so our optimizations
+    // can kick in.
+    if (rewrite == null)
+      regexpSource = regexpSource.replace(/^\*+/, "").replace(/\*+$/, "");
+
     if (!this.matchCase && isLiteralPattern(regexpSource))
       regexpSource = regexpSource.toLowerCase();
 
     // No need to convert this filter to regular expression yet, do it on demand
     this.pattern = regexpSource;
   }
 }
 exports.RegExpFilter = RegExpFilter;
@@ -1065,17 +1074,17 @@
  *   BlockingFilter.prototype.rewrite.
  * @constructor
  * @augments RegExpFilter
  */
 function BlockingFilter(text, regexpSource, contentType, matchCase, domains,
                         thirdParty, sitekeys, collapse, csp, rewrite)
 {
   RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains,
-                    thirdParty, sitekeys);
+                    thirdParty, sitekeys, rewrite);
 
   if (collapse != null)
     this.collapse = collapse;
 
   if (csp != null)
     this.csp = csp;
 
   if (rewrite != null)