[PATCH 08/11] net_if: Handle content-free <net/if.h> system headers

[Kevin Cernekee]

* m4/net_if_h.m4: Check to make sure <net/if.h> actually defines
struct if_nameindex.  If not, enable the replacement header.
---
 ChangeLog      | 4 ++++
 m4/net_if_h.m4 | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 8cd014b3cf58..d17b2220125b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,6 +42,10 @@
        linkat_nofollow: Add fallback case for cross compiling
        * m4/linkat.m4: Guess no for Darwin, yes otherwise.
 
+       net_if: Handle content-free <net/if.h> system headers
+       * m4/net_if_h.m4: Check to make sure <net/if.h> actually defines
+       struct if_nameindex.  If not, enable the replacement header.
+
 2015-02-08  Daiki Ueno  <address@hidden>
 
        uniname/unimame-tests: don't link with -lunistring
diff --git a/m4/net_if_h.m4 b/m4/net_if_h.m4
index b6ebc7333762..9db391c5fec6 100644
--- a/m4/net_if_h.m4
+++ b/m4/net_if_h.m4
@@ -9,7 +9,8 @@ AC_DEFUN([gl_HEADER_NET_IF],
   AC_CACHE_CHECK([whether <net/if.h> is self-contained],
     [gl_cv_header_net_if_h_selfcontained],
     [
-      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <net/if.h>]], [[]])],
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <net/if.h>]],
+                                         [[struct if_nameindex ni;]])],
         [gl_cv_header_net_if_h_selfcontained=yes],
         [gl_cv_header_net_if_h_selfcontained=no])
     ])
-- 
2.2.0.rc0.207.ga3a616c