Issue 6815 - Avoid multiple copies of domain maps

test/filterClasses.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 525 matching lines @@
              "foo$bar$csp=ba r");
   test.equal(Filter.normalize("f    $    o    $    o    $    csp=f o o "),
              "f$o$o$csp=f o o");
   test.equal(Filter.normalize("/foo$/$ csp = script-src  http://example.com/?$1=1&$2=2&$3=3"),
              "/foo$/$csp=script-src http://example.com/?$1=1&$2=2&$3=3");
   test.equal(Filter.normalize("||content.server.com/files/*.php$rewrite= $1"),
              "||content.server.com/files/*.php$rewrite=$1");
   test.done();
 };
 
-
 exports.testFilterRewriteOption = function(test)
 {
   let text = "/(content\\.server\\/file\\/.*\\.txt)\\?.*$/$rewrite=$1";
 
   let filter = Filter.fromText(text);
 
   test.equal(filter.rewrite, "$1");
   // no rewrite occured: didn't match.
   test.equal(filter.rewriteUrl("foo"), "foo");
   // rewrite occured: matched.
@@ skipping 39 matching lines @@
   let filterStrip = Filter.fromText(rewriteStrip);
 
   test.equal(filterStrip.rewrite, "");
   test.equal(
     filterStrip.rewriteUrl("http://example.com/?tag"),
     "http://example.com/?"
   );
 
   test.done();
 };
+
+exports.testDomainMapDeduplication = function(test)
+{
+  let filter1 = Filter.fromText("example.com##.foo");
+  let filter2 = Filter.fromText("example.com##.bar");
+
+  // This compares the references to make sure that both refer to the same
+  // object (#6815).
+  test.equal(filter1.domains, filter2.domains);
+
+  let filter3 = Filter.fromText("www.example.com##.bar");
+
+  test.notEqual(filter2.domains, filter3.domains);
+
+  test.done();
+};