ftw.c affected by g++/glibc issue __USE_GNU is defined.

When compiling as C++, __USE_GNU is defined even though
we use -ansi and don't specify -D_GNU_SOURCE anywhere.
Glibc headers don't seem to respond to the C++ ANSI options.

ftw.c: Workaround for compiler warning: only define
__USE_GNU if it is not defined already.

1 files changed, 2 insertions, 0 deletions

diff --git a/ftw.c b/ftw.c
index 7b18cebd..6128a652 100644
--- a/ftw.c
+++ b/ftw.c
@@ -29,7 +29,9 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <stddef.h>
+#ifndef __USE_GNU
 #define __USE_GNU
+#endif
 #include <ftw.h>
 #include "config.h"
 #include ALLOCA_H