From 6863fe9606ec4c13a0644ea347d8b1877cb5f9fc Mon Sep 17 00:00:00 2001
From: Enrico Forestieri <forenr@lyx.org>
Date: Sun, 26 Jun 2016 19:45:50 +0200
Subject: [PATCH] Fix build with autotools and gcc 6

---
 config/lyxinclude.m4 | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index c43ae99d80..629247b3e5 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -841,9 +841,17 @@ dnl Defines HAVE_DEF_{NAME}
 AC_DEFUN([LYX_CHECK_DEF],
 [LYX_AH_CHECK_DEF($1, $2)
  AC_MSG_CHECKING([whether $1 is defined by header $2])
+ save_CPPFLAGS=$CPPFLAGS
+ CPPFLAGS="$AM_CPPFLAGS $CPPFLAGS"
+ save_CXXFLAGS=$CXXFLAGS
+ CXXFLAGS="$AM_CXXFLAGS $CXXFLAGS"
+ AC_LANG_PUSH(C++)
  AC_TRY_COMPILE([#include <$2>], [$3],
      lyx_have_def_name=yes,
      lyx_have_def_name=no)
+ AC_LANG_POP(C++)
+ CXXFLAGS=$save_CXXFLAGS
+ CPPFLAGS=$save_CPPFLAGS
  AC_MSG_RESULT($lyx_have_def_name)
  if test "x$lyx_have_def_name" = xyes; then
    AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_DEF_$1))