From b9ac6725269b9726cb57e17ed164cda02d41f086 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Mon, 16 Nov 2015 13:29:57 -0500
Subject: [PATCH] Bug 1224580.  Copy of URLSearchParams should not copy its
 observer pointer.  r=baku

---
 dom/base/URLSearchParams.cpp            |  2 +-
 dom/base/test/test_urlSearchParams.html | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/dom/base/URLSearchParams.cpp b/dom/base/URLSearchParams.cpp
index 68af659a9370..d9f3132b5f49 100644
--- a/dom/base/URLSearchParams.cpp
+++ b/dom/base/URLSearchParams.cpp
@@ -315,7 +315,7 @@ URLSearchParams::URLSearchParams(nsISupports* aParent,
                                  const URLSearchParams& aOther)
   : mParams(new URLParams(*aOther.mParams.get()))
   , mParent(aParent)
-  , mObserver(aOther.mObserver)
+  , mObserver(nullptr)
 {
 }
 
diff --git a/dom/base/test/test_urlSearchParams.html b/dom/base/test/test_urlSearchParams.html
index e5333b7e5bf6..a3036f8076bf 100644
--- a/dom/base/test/test_urlSearchParams.html
+++ b/dom/base/test/test_urlSearchParams.html
@@ -300,6 +300,20 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=887836
     runTest();
   }
 
+  function testCopyConstructor() {
+    var url = new URL("http://example.com/");
+    var p = url.searchParams;
+    var q = new URLSearchParams(p);
+    q.set("a", "b");
+    is(url.href, "http://example.com/",
+       "Messing with copy of URLSearchParams should not affect URL");
+    p.set("c", "d");
+    is(url.href, "http://example.com/?c=d",
+       "Messing with URLSearchParams should affect URL");
+
+    runTest();
+  }
+
   var tests = [
     testSimpleURLSearchParams,
     testCopyURLSearchParams,
@@ -314,6 +328,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=887836
     testSet,
     testIterable,
     testZeroHandling,
+    testCopyConstructor,
   ];
 
   function runTest() {