From 60a1663f2267932e70665209910ddcec77a13bc3 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Sat, 6 Aug 2016 13:21:42 +0100
Subject: [PATCH] Fix construction of std::function from null pointer-to-member

	PR libstdc++/69293
	* include/std/functional (_Function_base::_M_not_empty_function):
	Change overloads for pointers to take arguments by value.
	* testsuite/20_util/function/cons/57465.cc: Add tests for
	pointer-to-member cases.

From-SVN: r239205
---
 libstdc++-v3/ChangeLog                        |  9 +++++++
 libstdc++-v3/include/std/functional           |  8 +++----
 .../testsuite/20_util/function/cons/57465.cc  | 24 +++++++++++++++----
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 4460748b28b9..ae8c9b9f7afe 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,14 @@
 2016-08-06  Jonathan Wakely  <jwakely@redhat.com>
 
+	Backport from mainline
+	2016-01-18  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/69243
+	* include/std/functional (_Function_base::_M_not_empty_function):
+	Change overloads for pointers to take arguments by value.
+	* testsuite/20_util/function/cons/57465.cc: Add tests for
+	pointer-to-member cases.
+
 	* doc/xml/manual/status_cxx2011.xml: Change "mainline GCC SVN" to
 	refer to the release series.
 	* doc/xml/manual/status_cxx2014.xml: Likewise.
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index cc40e4d8ec40..78f7073e8f7c 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1764,13 +1764,13 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
 	template<typename _Tp>
 	  static bool
-	  _M_not_empty_function(_Tp* const& __fp)
-	  { return __fp; }
+	  _M_not_empty_function(_Tp* __fp)
+	  { return __fp != nullptr; }
 
 	template<typename _Class, typename _Tp>
 	  static bool
-	  _M_not_empty_function(_Tp _Class::* const& __mp)
-	  { return __mp; }
+	  _M_not_empty_function(_Tp _Class::* __mp)
+	  { return __mp != nullptr; }
 
 	template<typename _Tp>
 	  static bool
diff --git a/libstdc++-v3/testsuite/20_util/function/cons/57465.cc b/libstdc++-v3/testsuite/20_util/function/cons/57465.cc
index ba04ed6ac2b0..eb5556e4d46a 100644
--- a/libstdc++-v3/testsuite/20_util/function/cons/57465.cc
+++ b/libstdc++-v3/testsuite/20_util/function/cons/57465.cc
@@ -15,17 +15,33 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// libstdc++/57465
-
 // { dg-options "-std=gnu++11" }
 
 #include <functional>
 #include <testsuite_hooks.h>
 
-int main()
+void test01()
 {
   using F = void();
   F* f = nullptr;
   std::function<F> x(f);
-  VERIFY( !x );
+  VERIFY( !x ); // libstdc++/57465
+}
+
+void test02()
+{
+  struct X { };
+  int (X::*mf)() = nullptr;
+  std::function<int(X&)> f = mf;
+  VERIFY( !f ); // libstdc++/69243
+
+  int X::*mp = nullptr;
+  f = mp;
+  VERIFY( !f );
+}
+
+int main()
+{
+  test01();
+  test02();
 }
-- 
2.47.2