Index: include/debug/macros.h
===================================================================
--- include/debug/macros.h	(revision 181967)
+++ include/debug/macros.h	(working copy)
@@ -57,6 +57,13 @@ _GLIBCXX_DEBUG_VERIFY(__gnu_debug::__val
 		      ._M_iterator(_First, #_First)			\
 		      ._M_iterator(_Last, #_Last))
 
+// Verify that [_First, _Last) forms a non-empty iterator range.
+#define __glibcxx_check_non_empty_range(_First,_Last)			\
+_GLIBCXX_DEBUG_VERIFY(_First != _Last,					\
+		      _M_message(__gnu_debug::__msg_non_empty_range)	\
+		      ._M_iterator(_First, #_First)			\
+		      ._M_iterator(_Last, #_Last))
+
 /** Verify that we can insert into *this with the iterator _Position.
  *  Insertion into a container at a specific position requires that
  *  the iterator be nonsingular, either dereferenceable or past-the-end,
Index: include/debug/debug.h
===================================================================
--- include/debug/debug.h	(revision 181967)
+++ include/debug/debug.h	(working copy)
@@ -1,6 +1,6 @@
 // Debugging support implementation -*- C++ -*-
 
-// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
 // Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
@@ -64,6 +64,7 @@ namespace __gnu_debug
 # define _GLIBCXX_DEBUG_ONLY(_Statement) ;
 # define __glibcxx_requires_cond(_Cond,_Msg)
 # define __glibcxx_requires_valid_range(_First,_Last)
+# define __glibcxx_requires_non_empty_range(_First,_Last)
 # define __glibcxx_requires_sorted(_First,_Last)
 # define __glibcxx_requires_sorted_pred(_First,_Last,_Pred)
 # define __glibcxx_requires_sorted_set(_First1,_Last1,_First2)
@@ -96,6 +97,8 @@ namespace __gnu_debug
 # define __glibcxx_requires_cond(_Cond,_Msg) _GLIBCXX_DEBUG_VERIFY(_Cond,_Msg)
 # define __glibcxx_requires_valid_range(_First,_Last) \
      __glibcxx_check_valid_range(_First,_Last)
+# define __glibcxx_requires_non_empty_range(_First,_Last) \
+     __glibcxx_check_non_empty_range(_First,_Last)
 # define __glibcxx_requires_sorted(_First,_Last) \
      __glibcxx_check_sorted(_First,_Last)
 # define __glibcxx_requires_sorted_pred(_First,_Last,_Pred) \
Index: include/debug/formatter.h
===================================================================
--- include/debug/formatter.h	(revision 181967)
+++ include/debug/formatter.h	(working copy)
@@ -108,7 +108,8 @@ namespace __gnu_debug
     __msg_erase_after_bad,
     __msg_valid_range2,
     // unordered sequence local iterators
-    __msg_local_iter_compare_bad
+    __msg_local_iter_compare_bad,
+    __msg_non_empty_range
   };
 
   class _Error_formatter
Index: src/debug.cc
===================================================================
--- src/debug.cc	(revision 181967)
+++ src/debug.cc	(working copy)
@@ -176,7 +176,8 @@ namespace __gnu_debug
     ", \"%2.name;\" shall be before and not equal to \"%3.name;\"",
     // std::unordered_container::local_iterator
     "attempt to compare local iterators from different unordered container"
-    " buckets"
+    " buckets",
+    "function requires a non-empty iterator range [%1.name;, %2.name;)"
   };
 
   void
Index: include/bits/stl_heap.h
===================================================================
--- include/bits/stl_heap.h	(revision 181967)
+++ include/bits/stl_heap.h	(working copy)
@@ -1,7 +1,7 @@
 // Heap implementation -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
-// Free Software Foundation, Inc.
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+// 2011 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -270,6 +270,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  @brief  Pop an element off a heap.
    *  @param  __first  Start of heap.
    *  @param  __last   End of heap.
+   *  @pre    [__first, __last) is a valid, non-empty range.
    *  @ingroup heap_algorithms
    *
    *  This operation pops the top of the heap.  The elements __first
@@ -287,6 +288,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
 	    _RandomAccessIterator>)
       __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>)
+      __glibcxx_requires_non_empty_range(__first, __last);
       __glibcxx_requires_valid_range(__first, __last);
       __glibcxx_requires_heap(__first, __last);
 
Index: testsuite/25_algorithms/pop_heap/empty_neg.cc
===================================================================
--- testsuite/25_algorithms/pop_heap/empty_neg.cc	(revision 0)
+++ testsuite/25_algorithms/pop_heap/empty_neg.cc	(revision 0)
@@ -0,0 +1,37 @@
+// Copyright (C) 2011 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without Pred the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 25.3.6 Heap operations [lib.alg.heap.operations]
+
+// { dg-require-debug-mode "" }
+// { dg-do run { xfail *-*-* } }
+
+#include <algorithm>
+
+void
+test01()
+{
+  int i = 0;
+  std::pop_heap(&i, &i);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}
