diff -r 000000000000 -r 6474c204b198 extensions/cookie/test/unit/test_permmanager_idn.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extensions/cookie/test/unit/test_permmanager_idn.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,48 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function getPrincipalFromDomain(aDomain) {
+  return Cc["@mozilla.org/scriptsecuritymanager;1"]
+           .getService(Ci.nsIScriptSecurityManager)
+           .getNoAppCodebasePrincipal(NetUtil.newURI("http://" + aDomain));
+}
+
+function run_test() {
+  let profile = do_get_profile();
+  let pm = Services.perms;
+  let perm = 'test-idn';
+
+  // We create three principal linked to IDN.
+  // One with just a domain, one with a subdomain and one with the TLD
+  // containing a UTF-8 character.
+  let mainDomainPrincipal = getPrincipalFromDomain("fôû.com");
+  let subDomainPrincipal = getPrincipalFromDomain("fôô.bàr.com");
+  let tldPrincipal = getPrincipalFromDomain("fôû.bàr.côm");
+
+  // We add those to the permission manager.
+  pm.addFromPrincipal(mainDomainPrincipal, perm, pm.ALLOW_ACTION, 0, 0);
+  pm.addFromPrincipal(subDomainPrincipal, perm, pm.ALLOW_ACTION, 0, 0);
+  pm.addFromPrincipal(tldPrincipal, perm, pm.ALLOW_ACTION, 0, 0);
+
+  // They should obviously be there now..
+  do_check_eq(pm.testPermissionFromPrincipal(mainDomainPrincipal, perm), pm.ALLOW_ACTION);
+  do_check_eq(pm.testPermissionFromPrincipal(subDomainPrincipal, perm), pm.ALLOW_ACTION);
+  do_check_eq(pm.testPermissionFromPrincipal(tldPrincipal, perm), pm.ALLOW_ACTION);
+
+  // We do the same thing with the puny-encoded versions of the IDN.
+  let punyMainDomainPrincipal = getPrincipalFromDomain('xn--f-xgav.com');
+  let punySubDomainPrincipal = getPrincipalFromDomain('xn--f-xgaa.xn--br-jia.com');
+  let punyTldPrincipal = getPrincipalFromDomain('xn--f-xgav.xn--br-jia.xn--cm-8ja');
+
+  // Those principals should have the permission granted too.
+  do_check_eq(pm.testPermissionFromPrincipal(punyMainDomainPrincipal, perm), pm.ALLOW_ACTION);
+  do_check_eq(pm.testPermissionFromPrincipal(punySubDomainPrincipal, perm), pm.ALLOW_ACTION);
+  do_check_eq(pm.testPermissionFromPrincipal(punyTldPrincipal, perm), pm.ALLOW_ACTION);
+
+  // However, those two principals shouldn't be allowed because they are like
+  // the IDN but without the UT8-8 characters.
+  let witnessPrincipal = getPrincipalFromDomain("foo.com");
+  do_check_eq(pm.testPermissionFromPrincipal(witnessPrincipal, perm), pm.UNKNOWN_ACTION);
+  witnessPrincipal = getPrincipalFromDomain("foo.bar.com");
+  do_check_eq(pm.testPermissionFromPrincipal(witnessPrincipal, perm), pm.UNKNOWN_ACTION);
+}
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