[!__STDC__]: Define const only if not defined.

diff --git a/libio/libio.h b/libio/libio.h
index 20eb5a9e1aecc48dfd04bee4c9e41ebf44b4e8d4..fe290623ac40947655f9ffc0a93528506f178c30 100644 (file)
--- a/libio/libio.h
+++ b/libio/libio.h
@@ -69,8 +69,10 @@ the executable file might be covered by the GNU General Public License. */
 #endif /*!_PARAMS*/
 
 #ifndef __STDC__
+#ifndef const
 #define const
 #endif
+#endif
 #define _IO_UNIFIED_JUMPTABLES 1
 
 #if 0