commit 235acd98b73cf2794b9341c0337ca82f4d807620
Author: ChangZhuo Chen <czchen@gmail.com>
Date:   Sat Dec 1 21:49:58 2012 +0800

    Work around unused variable warnings

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index 02b999e..37ce006 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1286,6 +1286,8 @@ test_varargs (const char *format, ...)
 	  break;
 	}
     }
+  // work around unused variable warnings
+  printf("%s%d%f", str, number, fnumber);
   va_end (args_copy);
   va_end (args);
 }]])# _AC_C_C99_TEST_HEADER