diff --git a/xpcom/base/nsAutoPtr.h b/xpcom/base/nsAutoPtr.h
index 7a9a9bd1a3d..b85bf345bbd 100644
--- a/xpcom/base/nsAutoPtr.h
+++ b/xpcom/base/nsAutoPtr.h
@@ -1000,6 +1000,14 @@ class nsRefPtr
         {
         }
 
+      nsRefPtr( const nsCOMPtr_helper& helper )
+        {
+          void* newRawPtr;
+          if (NS_FAILED(helper(NS_GET_TEMPLATE_IID(T), &newRawPtr)))
+            newRawPtr = 0;
+          mRawPtr = static_cast<T*>(newRawPtr);
+        }
+
         // Assignment operators
 
       nsRefPtr<T>&
@@ -1027,6 +1035,16 @@ class nsRefPtr
           return *this;
         }
 
+      nsRefPtr<T>&
+      operator=( const nsCOMPtr_helper& helper )
+        {
+          void* newRawPtr;
+          if (NS_FAILED(helper(NS_GET_TEMPLATE_IID(T), &newRawPtr)))
+            newRawPtr = 0;
+          assign_assuming_AddRef(static_cast<T*>(newRawPtr));
+          return *this;
+        }
+
         // Other pointer operators
 
       void
@@ -1429,4 +1447,89 @@ CallQueryInterface( nsRefPtr<SourceType>& aSourcePtr, DestinationType** aDestPtr
 
 /*****************************************************************************/
 
+template<class T>
+class nsQueryObject : public nsCOMPtr_helper
+{
+public:
+  nsQueryObject(T* aRawPtr)
+    : mRawPtr(aRawPtr) {}
+
+  virtual nsresult NS_FASTCALL operator()( const nsIID& aIID, void** aResult ) const {
+    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
+                              : NS_ERROR_NULL_POINTER;
+    return status;
+  }
+private:
+  T* mRawPtr;
+};
+
+template<class T>
+class nsQueryObjectWithError : public nsCOMPtr_helper
+{
+public:
+  nsQueryObjectWithError(T* aRawPtr, nsresult* aErrorPtr)
+    : mRawPtr(aRawPtr), mErrorPtr(aErrorPtr) {}
+
+  virtual nsresult NS_FASTCALL operator()( const nsIID& aIID, void** aResult ) const {
+    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
+                              : NS_ERROR_NULL_POINTER;
+    if (mErrorPtr)
+      *mErrorPtr = status;
+    return status;
+  }
+private:
+  T* mRawPtr;
+  nsresult* mErrorPtr;
+};
+
+template<class T>
+inline
+nsQueryObject<T>
+do_QueryObject(T* aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline
+nsQueryObject<T>
+do_QueryObject(nsCOMPtr<T>& aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline
+nsQueryObject<T>
+do_QueryObject(nsRefPtr<T>& aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline
+nsQueryObjectWithError<T>
+do_QueryObject(T* aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+template<class T>
+inline
+nsQueryObjectWithError<T>
+do_QueryObject(nsCOMPtr<T>& aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+template<class T>
+inline
+nsQueryObjectWithError<T>
+do_QueryObject(nsRefPtr<T>& aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+/*****************************************************************************/
+
 #endif // !defined(nsAutoPtr_h___)
diff --git a/xpcom/tests/Makefile.in b/xpcom/tests/Makefile.in
index 3461804498e..ec586a80568 100644
--- a/xpcom/tests/Makefile.in
+++ b/xpcom/tests/Makefile.in
@@ -92,6 +92,7 @@ CPP_UNIT_TESTS = \
                  TestObserverArray.cpp \
                  TestObserverService.cpp \
                  TestPipe.cpp \
+                 TestRefPtr.cpp \
                  TestServMgr.cpp \
                  TestTextFormatter.cpp \
                  $(NULL)
diff --git a/xpcom/tests/TestRefPtr.cpp b/xpcom/tests/TestRefPtr.cpp
new file mode 100644
index 00000000000..3f9504be1ff
--- /dev/null
+++ b/xpcom/tests/TestRefPtr.cpp
@@ -0,0 +1,597 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Pierre Phaneuf <pp@ludusdesign.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include <assert.h>
+#include <stdio.h>
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+#include "nsISupports.h"
+
+#ifdef HAVE_CPP_NEW_CASTS
+  #define STATIC_CAST(T,x)  static_cast<T>(x)
+  #define REINTERPRET_CAST(T,x) reinterpret_cast<T>(x)
+#else
+  #define STATIC_CAST(T,x)  ((T)(x))
+  #define REINTERPRET_CAST(T,x) ((T)(x))
+#endif
+
+
+#define NS_FOO_IID \
+{ 0x6f7652e0,  0xee43, 0x11d1, \
+ { 0x9c, 0xc3, 0x00, 0x60, 0x08, 0x8c, 0xa6, 0xb3 } }
+
+class Foo : public nsISupports
+  {
+		public:
+			NS_DECLARE_STATIC_IID_ACCESSOR(NS_FOO_IID)
+
+		public:
+      Foo();
+      // virtual dtor because Bar uses our Release()
+      virtual ~Foo();
+
+      NS_IMETHOD_(nsrefcnt) AddRef();
+      NS_IMETHOD_(nsrefcnt) Release();
+      NS_IMETHOD QueryInterface( const nsIID&, void** );
+
+      static void print_totals();
+
+    private:
+      unsigned int refcount_;
+
+      static unsigned int total_constructions_;
+      static unsigned int total_destructions_;
+  };
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Foo, NS_FOO_IID)
+
+class Bar;
+
+  // some types I'll need
+typedef unsigned long NS_RESULT;
+
+  // some functions I'll need (and define below)
+          nsresult  CreateFoo( void** );
+          nsresult  CreateBar( void** result );
+              void  AnFooPtrPtrContext( Foo** );
+              void	AnISupportsPtrPtrContext( nsISupports** );
+              void  AVoidPtrPtrContext( void** );
+              void  set_a_Foo( nsRefPtr<Foo>* result );
+nsRefPtr<Foo>  return_a_Foo();
+
+
+
+
+unsigned int Foo::total_constructions_;
+unsigned int Foo::total_destructions_;
+
+class test_message
+  {
+    public:
+      test_message()
+        {
+          printf("BEGIN unit tests for |nsRefPtr|, compiled " __DATE__ "\n");
+        }
+
+     ~test_message()
+        {
+          Foo::print_totals();
+          printf("END unit tests for |nsRefPtr|.\n");
+        }
+  };
+
+test_message gTestMessage;
+
+
+  /*
+    ...
+  */
+
+void
+Foo::print_totals()
+  {
+    printf("total constructions/destructions --> %d/%d\n", 
+           total_constructions_, total_destructions_);
+  }
+
+Foo::Foo()
+    : refcount_(0)
+  {
+    ++total_constructions_;
+    printf("  new Foo@%p [#%d]\n",
+           STATIC_CAST(void*, this), total_constructions_);
+  }
+
+Foo::~Foo()
+  {
+    ++total_destructions_;
+    printf("Foo@%p::~Foo() [#%d]\n",
+           STATIC_CAST(void*, this), total_destructions_);
+  }
+
+nsrefcnt
+Foo::AddRef()
+  {
+    ++refcount_;
+    printf("Foo@%p::AddRef(), refcount --> %d\n",
+           STATIC_CAST(void*, this), refcount_);
+    return refcount_;
+  }
+
+nsrefcnt
+Foo::Release()
+  {
+    int newcount = --refcount_;
+    if ( newcount == 0 )
+      printf(">>");
+
+    printf("Foo@%p::Release(), refcount --> %d\n",
+           STATIC_CAST(void*, this), refcount_);
+
+    if ( newcount == 0 )
+      {
+        printf("  delete Foo@%p\n", STATIC_CAST(void*, this));
+        printf("<<Foo@%p::Release()\n", STATIC_CAST(void*, this));
+        delete this;
+      }
+
+    return newcount;
+  }
+
+nsresult
+Foo::QueryInterface( const nsIID& aIID, void** aResult )
+	{
+    printf("Foo@%p::QueryInterface()\n", STATIC_CAST(void*, this));
+		nsISupports* rawPtr = 0;
+		nsresult status = NS_OK;
+
+		if ( aIID.Equals(GetIID()) )
+			rawPtr = this;
+		else
+			{
+				nsID iid_of_ISupports = NS_ISUPPORTS_IID;
+				if ( aIID.Equals(iid_of_ISupports) )
+					rawPtr = STATIC_CAST(nsISupports*, this);
+				else
+					status = NS_ERROR_NO_INTERFACE;
+			}
+
+		NS_IF_ADDREF(rawPtr);
+		*aResult = rawPtr;
+
+		return status;
+	}
+
+nsresult
+CreateFoo( void** result )
+    // a typical factory function (that calls AddRef)
+  {
+    printf(">>CreateFoo() --> ");
+    Foo* foop = new Foo;
+    printf("Foo@%p\n", STATIC_CAST(void*, foop));
+
+    foop->AddRef();
+    *result = foop;
+
+    printf("<<CreateFoo()\n");
+    return 0;
+  }
+
+void
+set_a_Foo( nsRefPtr<Foo>* result )
+  {
+    printf(">>set_a_Foo()\n");
+    assert(result);
+
+    nsRefPtr<Foo> foop( do_QueryObject(new Foo) );
+    *result = foop;
+    printf("<<set_a_Foo()\n");
+  }
+
+nsRefPtr<Foo>
+return_a_Foo()
+  {
+    printf(">>return_a_Foo()\n");
+    nsRefPtr<Foo> foop( do_QueryObject(new Foo) );
+    printf("<<return_a_Foo()\n");
+    return foop;
+  }
+
+
+
+
+#define NS_BAR_IID \
+{ 0x6f7652e1,  0xee43, 0x11d1, \
+ { 0x9c, 0xc3, 0x00, 0x60, 0x08, 0x8c, 0xa6, 0xb3 } }
+
+class Bar : public Foo
+  {
+  	public:
+		NS_DECLARE_STATIC_IID_ACCESSOR(NS_BAR_IID)
+
+    public:
+      Bar();
+      virtual ~Bar();
+
+      NS_IMETHOD QueryInterface( const nsIID&, void** );
+  };
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Bar, NS_BAR_IID)
+
+Bar::Bar()
+  {
+    printf("  new Bar@%p\n", STATIC_CAST(void*, this));
+  }
+
+Bar::~Bar()
+  {
+    printf("Bar@%p::~Bar()\n", STATIC_CAST(void*, this));
+  }
+
+nsresult
+Bar::QueryInterface( const nsID& aIID, void** aResult )
+	{
+    printf("Bar@%p::QueryInterface()\n", STATIC_CAST(void*, this));
+		nsISupports* rawPtr = 0;
+		nsresult status = NS_OK;
+
+		if ( aIID.Equals(GetIID()) )
+			rawPtr = this;
+		else if ( aIID.Equals(NS_GET_IID(Foo)) )
+			rawPtr = STATIC_CAST(Foo*, this);
+		else
+			{
+				nsID iid_of_ISupports = NS_ISUPPORTS_IID;
+				if ( aIID.Equals(iid_of_ISupports) )
+					rawPtr = STATIC_CAST(nsISupports*, this);
+				else
+					status = NS_ERROR_NO_INTERFACE;
+			}
+
+		NS_IF_ADDREF(rawPtr);
+		*aResult = rawPtr;
+
+		return status;
+	}
+
+
+
+nsresult
+CreateBar( void** result )
+    // a typical factory function (that calls AddRef)
+  {
+    printf(">>CreateBar() --> ");
+    Bar* barp = new Bar;
+    printf("Bar@%p\n", STATIC_CAST(void*, barp));
+
+    barp->AddRef();
+    *result = barp;
+
+    printf("<<CreateBar()\n");
+    return 0;
+  }
+
+void
+AnFooPtrPtrContext( Foo** )
+  {
+  }
+
+void
+AVoidPtrPtrContext( void** )
+  {
+  }
+
+void
+AnISupportsPtrPtrContext( nsISupports** )
+	{
+	}
+
+nsresult
+TestBloat_Raw_Unsafe()
+	{
+		Bar* barP = 0;
+		nsresult result = CreateBar(REINTERPRET_CAST(void**, &barP));
+
+		if ( barP )
+			{
+				Foo* fooP = 0;
+				if ( NS_SUCCEEDED( result = barP->QueryInterface(NS_GET_IID(Foo), REINTERPRET_CAST(void**, &fooP)) ) )
+					{
+						fooP->print_totals();
+						NS_RELEASE(fooP);
+					}
+
+				NS_RELEASE(barP);
+			}
+
+		return result;
+	}
+
+
+static
+nsresult
+TestBloat_Smart()
+	{
+		nsRefPtr<Bar> barP;
+		nsresult result = CreateBar( getter_AddRefs(barP) );
+
+		nsRefPtr<Foo> fooP( do_QueryObject(barP, &result) );
+
+		if ( fooP )
+			fooP->print_totals();
+
+		return result;
+	}
+
+
+
+
+nsRefPtr<Foo> gFoop;
+
+int
+main()
+  {
+    printf(">>main()\n");
+
+		printf("sizeof(nsRefPtr<Foo>) --> %d\n", sizeof(nsRefPtr<Foo>));
+
+		TestBloat_Raw_Unsafe();
+		TestBloat_Smart();
+
+
+    {
+      printf("\n### Test  1: will a |nsCOMPtr| call |AddRef| on a pointer assigned into it?\n");
+      nsRefPtr<Foo> foop( do_QueryObject(new Foo) );
+
+      printf("\n### Test  2: will a |nsCOMPtr| |Release| its old pointer when a new one is assigned in?\n");
+      foop = do_QueryObject(new Foo);
+
+        // [Shouldn't compile] Is it a compile time error to try to |AddRef| by hand?
+      //foop->AddRef();
+
+        // [Shouldn't compile] Is it a compile time error to try to |Release| be hand?
+      //foop->Release();
+
+				// [Shouldn't compile] Is it a compile time error to try to |delete| an |nsCOMPtr|?
+			//delete foop;
+
+      printf("\n### Test  3: can you |AddRef| if you must?\n");
+      STATIC_CAST(Foo*, foop)->AddRef();
+
+      printf("\n### Test  4: can you |Release| if you must?\n");
+      STATIC_CAST(Foo*, foop)->Release();
+
+      printf("\n### Test  5: will a |nsCOMPtr| |Release| when it goes out of scope?\n");
+    }
+
+    {
+      printf("\n### Test  6: will a |nsCOMPtr| call the correct destructor?\n");
+      nsRefPtr<Foo> foop( do_QueryObject(new Bar) );
+    }
+
+    {
+      printf("\n### Test  7: can you compare one |nsCOMPtr| with another [!=]?\n");
+
+      nsRefPtr<Foo> foo1p( do_QueryObject(new Foo) );
+
+        // [Shouldn't compile] Is it a compile time error to omit |getter_[doesnt_]AddRef[s]|?
+      //AnFooPtrPtrContext(&foo1p);
+
+        // [Shouldn't compile] Is it a compile time error to omit |getter_[doesnt_]AddRef[s]|?
+      //AVoidPtrPtrContext(&foo1p);
+
+      nsRefPtr<Foo> foo2p( do_QueryObject(new Foo) );
+
+      if ( foo1p != foo2p )
+        printf("foo1p != foo2p\n");
+      else
+        printf("foo1p == foo2p\n");
+
+      printf("\n### Test  7.5: can you compare a |nsCOMPtr| with NULL, 0, nsnull [!=]?\n");
+      if ( foo1p != 0 )
+      	printf("foo1p != 0\n");
+      if ( 0 != foo1p )
+      	printf("0 != foo1p\n");
+      if ( foo1p == 0 )
+      	printf("foo1p == 0\n");
+      if ( 0 == foo1p )
+      	printf("0 == foo1p\n");
+			
+
+      Foo* raw_foo2p = foo2p.get();
+
+      printf("\n### Test  8: can you compare a |nsCOMPtr| with a raw interface pointer [!=]?\n");
+      if ( foo1p.get() != raw_foo2p )
+        printf("foo1p != raw_foo2p\n");
+      else
+        printf("foo1p == raw_foo2p\n");
+
+
+      printf("\n### Test  9: can you assign one |nsCOMPtr| into another?\n");
+      foo1p = foo2p;
+
+      printf("\n### Test 10: can you compare one |nsCOMPtr| with another [==]?\n");
+      if ( foo1p == foo2p )
+        printf("foo1p == foo2p\n");
+      else
+        printf("foo1p != foo2p\n");
+
+      printf("\n### Test 11: can you compare a |nsCOMPtr| with a raw interface pointer [==]?\n");
+      if ( raw_foo2p == foo2p.get() )
+        printf("raw_foo2p == foo2p\n");
+      else
+        printf("raw_foo2p != foo2p\n");
+
+#if 1
+      printf("\n### Test 11.5: can you compare a |nsCOMPtr| with a raw interface pointer [==]?\n");
+      if ( nsRefPtr<Foo>( raw_foo2p ) == foo2p )
+        printf("raw_foo2p == foo2p\n");
+      else
+        printf("raw_foo2p != foo2p\n");
+#endif
+
+      printf("\n### Test 12: bare pointer test?\n");
+      if ( foo1p )
+        printf("foo1p is not NULL\n");
+      else
+        printf("foo1p is NULL\n");
+
+      printf("\n### Test 13: numeric pointer test?\n");
+      if ( foo1p == 0 )
+        printf("foo1p is NULL\n");
+      else
+        printf("foo1p is not NULL\n");
+
+#if 0
+			if ( foo1p == 1 )
+				printf("foo1p allowed compare with in\n");
+#endif
+
+      printf("\n### Test 14: how about when two |nsCOMPtr|s referring to the same object go out of scope?\n");
+    }
+
+    {
+      printf("\n### Test 15,16 ...setup...\n");
+      Foo* raw_foo1p = new Foo;
+      raw_foo1p->AddRef();
+
+      Foo* raw_foo2p = new Foo;
+      raw_foo2p->AddRef();
+
+      printf("\n### Test 15: what if I don't want to |AddRef| when I construct?\n");
+      nsRefPtr<Foo> foo1p( dont_AddRef(raw_foo1p) );
+      //nsRefPtr<Foo> foo1p = dont_AddRef(raw_foo1p);
+
+      printf("\n### Test 16: what if I don't want to |AddRef| when I assign in?\n");
+      nsRefPtr<Foo> foo2p;
+      foo2p = dont_AddRef(raw_foo2p);
+    }
+
+
+
+
+
+
+
+    {
+    	printf("\n### setup for Test 17\n");
+      nsRefPtr<Foo> foop;
+      printf("### Test 17: basic parameter behavior?\n");
+      CreateFoo( nsRefPtrGetterAddRefs<Foo>(foop) );
+    }
+    printf("### End Test 17\n");
+
+
+    {
+    	printf("\n### setup for Test 18\n");
+      nsRefPtr<Foo> foop;
+      printf("### Test 18: basic parameter behavior, using the short form?\n");
+      CreateFoo( getter_AddRefs(foop) );
+    }
+    printf("### End Test 18\n");
+
+
+    {
+    	printf("\n### setup for Test 19, 20\n");
+      nsRefPtr<Foo> foop;
+      printf("### Test 19: reference parameter behavior?\n");
+      set_a_Foo(address_of(foop));
+
+      printf("### Test 20: return value behavior?\n");
+      foop = return_a_Foo();
+    }
+    printf("### End Test 19, 20\n");
+
+		{
+    	printf("\n### setup for Test 21\n");
+			nsRefPtr<Foo> fooP;
+
+			printf("### Test 21: is |QueryInterface| called on assigning in a raw pointer?\n");
+			fooP = do_QueryObject(new Foo);
+		}
+    printf("### End Test 21\n");
+
+		{
+    	printf("\n### setup for Test 22\n");
+			nsRefPtr<Foo> fooP;
+			fooP = do_QueryObject(new Foo);
+
+			nsRefPtr<Foo> foo2P;
+
+			printf("### Test 22: is |QueryInterface| _not_ called when assigning in a smart-pointer of the same type?\n");
+			foo2P = fooP;
+		}
+    printf("### End Test 22\n");
+
+		{
+    	printf("\n### setup for Test 23\n");
+			nsRefPtr<Bar> barP( do_QueryObject(new Bar) );
+
+			printf("### Test 23: is |QueryInterface| called when assigning in a smart-pointer of a different type?\n");
+
+			nsRefPtr<Foo> fooP( do_QueryObject(barP) );
+			if ( fooP )
+				printf("an Bar* is an Foo*\n");
+		}
+    printf("### End Test 23\n");
+
+
+		{
+    	printf("\n### setup for Test 24\n");
+			nsRefPtr<Foo> fooP( do_QueryObject(new Foo) );
+
+			printf("### Test 24: does |forget| avoid an AddRef/Release when assigning to another nsCOMPtr?\n");
+      nsRefPtr<Foo> fooP2( fooP.forget() );
+		}
+    printf("### End Test 24\n");
+
+		{
+			nsRefPtr<Foo> fooP;
+
+			AnFooPtrPtrContext( getter_AddRefs(fooP) );
+			AVoidPtrPtrContext( getter_AddRefs(fooP) );
+		}
+
+
+    printf("\n### Test 25: will a static |nsCOMPtr| |Release| before program termination?\n");
+    gFoop = do_QueryObject(new Foo);
+    
+    printf("<<main()\n");
+    return 0;
+  }
+