diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 03b71fe95..3c3b53a02 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,22 @@
+2009-08-05  Christopher Faylor  <me+cygwin@cgf.cx>
+
+	* cygheap.h (cygheap_debug::endh): Delete.
+	* debug.cc (lock_debug::acquired): Delete.
+	(lock_debug::lock_debug): Simplify.
+	(lock_debug::unlock): Ditto.
+	(find_handle): Don't set endh here.
+	(add_handle): Add new handle to beginning of the list rather than
+	trying to maintain an end list pointer.
+	(delete_handle): Minor optimization.
+	(mark_closed): Make logic clearer.
+	(verify_handle): Lock handle list before scanning.
+	(setclexec): Ditto.
+	(modify_handle): Ditto.
+	(newh): Don't lock handle list here.  Assume caller did this.
+	(mark_closed): Ditto.
+	(close_handle): Remove unneeded #if.
+	* dtable.cc (dtable::dup2): Tweak debug output.
+
 2009-08-04  Christopher Faylor  <me+cygwin@cgf.cx>
 
 	* path.cc (patch_conv::check): Zero path before setting it.
diff --git a/winsup/cygwin/cygheap.h b/winsup/cygwin/cygheap.h
index 6e01967f8..9bba99a65 100644
--- a/winsup/cygwin/cygheap.h
+++ b/winsup/cygwin/cygheap.h
@@ -230,7 +230,6 @@ public:
 struct cygheap_debug
 {
   handle_list starth;
-  handle_list *endh;
   handle_list freeh[500];
 };
 #endif
diff --git a/winsup/cygwin/debug.cc b/winsup/cygwin/debug.cc
index 232a7b838..bea256cae 100644
--- a/winsup/cygwin/debug.cc
+++ b/winsup/cygwin/debug.cc
@@ -27,20 +27,14 @@ details. */
 class lock_debug
 {
   static muto locker;
-  bool acquired;
  public:
-  lock_debug () : acquired (0)
+  lock_debug ()
   {
-    if (locker.name && !exit_state)
-      acquired = !!locker.acquire (INFINITE);
+    locker.acquire (INFINITE);
   }
   void unlock ()
   {
-    if (locker.name && acquired)
-      {
-	locker.release ();
-	acquired = false;
-      }
+    locker.release ();
   }
   ~lock_debug () {unlock ();}
   friend void debug_init ();
@@ -64,7 +58,6 @@ find_handle (HANDLE h)
   for (hl = &cygheap->debug.starth; hl->next != NULL; hl = hl->next)
     if (hl->next->h == h)
       goto out;
-  cygheap->debug.endh = hl;
   hl = NULL;
 
 out:
@@ -74,6 +67,7 @@ out:
 void
 verify_handle (const char *func, int ln, HANDLE h)
 {
+  lock_debug here;
   handle_list *hl = find_handle (h);
   if (!hl)
     return;
@@ -86,6 +80,7 @@ verify_handle (const char *func, int ln, HANDLE h)
 void
 setclexec (HANDLE oh, HANDLE nh, bool not_inheriting)
 {
+  lock_debug here;
   handle_list *hl = find_handle (oh);
   if (hl)
     {
@@ -100,7 +95,6 @@ static handle_list * __stdcall
 newh ()
 {
   handle_list *hl;
-  lock_debug here;
 
   for (hl = cygheap->debug.freeh; hl < cygheap->debug.freeh + NFREEH; hl++)
     if (hl->name == NULL)
@@ -112,6 +106,7 @@ newh ()
 void __stdcall
 modify_handle (const char *func, int ln, HANDLE h, const char *name, bool inh)
 {
+  lock_debug here;
   handle_list *hl = find_handle (h);
   if (!hl)
     {
@@ -128,11 +123,11 @@ void __stdcall
 add_handle (const char *func, int ln, HANDLE h, const char *name, bool inh)
 {
   handle_list *hl;
-  lock_debug here;
 
   if (!cygheap)
     return;
 
+  lock_debug here;
   if ((hl = find_handle (h)))
     {
       hl = hl->next;
@@ -156,11 +151,10 @@ add_handle (const char *func, int ln, HANDLE h, const char *name, bool inh)
   hl->name = name;
   hl->func = func;
   hl->ln = ln;
-  hl->next = NULL;
   hl->inherited = inh;
   hl->pid = GetCurrentProcessId ();
-  cygheap->debug.endh->next = hl;
-  cygheap->debug.endh = hl;
+  hl->next = cygheap->debug.starth.next;
+  cygheap->debug.starth.next = hl;
   SetHandleInformation (h, HANDLE_FLAG_PROTECT_FROM_CLOSE, HANDLE_FLAG_PROTECT_FROM_CLOSE);
   debug_printf ("protecting handle '%s'(%p), inherited flag %d", hl->name, hl->h, hl->inherited);
 }
@@ -170,7 +164,7 @@ delete_handle (handle_list *hl)
 {
   handle_list *hnuke = hl->next;
   debug_printf ("nuking handle '%s' (%p)", hnuke->name, hnuke->h);
-  hl->next = hl->next->next;
+  hl->next = hnuke->next;
   memset (hnuke, 0, sizeof (*hnuke));
 }
 
@@ -190,7 +184,6 @@ static bool __stdcall
 mark_closed (const char *func, int ln, HANDLE h, const char *name, bool force)
 {
   handle_list *hl;
-  lock_debug here;
 
   if (!cygheap)
     return true;
@@ -198,7 +191,6 @@ mark_closed (const char *func, int ln, HANDLE h, const char *name, bool force)
   if ((hl = find_handle (h)) && !force)
     {
       hl = hl->next;
-      here.unlock ();	// race here
       system_printf ("attempt to close protected handle %s:%d(%s<%p>) winpid %d",
 		     hl->func, hl->ln, hl->name, hl->h, hl->pid);
       system_printf (" by %s:%d(%s<%p>)", func, ln, name, h);
@@ -206,7 +198,7 @@ mark_closed (const char *func, int ln, HANDLE h, const char *name, bool force)
     }
 
   handle_list *hln;
-  if (hl && (hln = hl->next) && strcmp (name, hln->name))
+  if (hl && (hln = hl->next) && strcmp (name, hln->name) != 0)
     {
       system_printf ("closing protected handle %s:%d(%s<%p>)",
 		     hln->func, hln->ln, hln->name, hln->h);
@@ -225,18 +217,16 @@ bool __stdcall
 close_handle (const char *func, int ln, HANDLE h, const char *name, bool force)
 {
   bool ret;
-  lock_debug here;
 
+  lock_debug here;
   if (!mark_closed (func, ln, h, name, force))
     return false;
 
   SetHandleInformation (h, HANDLE_FLAG_PROTECT_FROM_CLOSE, 0);
   ret = CloseHandle (h);
 
-#if 1 /* Uncomment to see CloseHandle failures */
   if (!ret)
     small_printf ("CloseHandle(%s<%p>) failed %s:%d, %E\n", name, h, func, ln);
-#endif
   return ret;
 }
 #endif /*DEBUGGING*/
diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
index c361d01da..aa4c6e7f6 100644
--- a/winsup/cygwin/dtable.cc
+++ b/winsup/cygwin/dtable.cc
@@ -631,8 +631,8 @@ dtable::dup2 (int oldfd, int newfd)
       goto done;
     }
 
-  debug_printf ("newfh->io_handle %p, oldfh->io_handle %p",
-		newfh->get_io_handle (), fds[oldfd]->get_io_handle ());
+  debug_printf ("newfh->io_handle %p, oldfh->io_handle %p, new win32_name %p, old win32_name %p",
+		newfh->get_io_handle (), fds[oldfd]->get_io_handle (), newfh->get_win32_name (), fds[oldfd]->get_win32_name ());
 
   if (!not_open (newfd))
     close (newfd);