$OpenBSD: patch-gcc_dbxout_c,v 1.4 2009/04/16 18:36:48 espie Exp $
--- gcc/dbxout.c.orig	Mon Sep 24 11:17:10 2007
+++ gcc/dbxout.c	Tue Apr  7 19:38:59 2009
@@ -1007,7 +1007,7 @@ dbxout_init (const char *input_file_name)
 	  if (cwd[0] == '\0')
 	    cwd = "/";
 	  else if (!IS_DIR_SEPARATOR (cwd[strlen (cwd) - 1]))
-	    cwd = concat (cwd, "/", NULL);
+	    cwd = concat (cwd, "/", (void *)0);
 	}
 #ifdef DBX_OUTPUT_MAIN_SOURCE_DIRECTORY
       DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (asm_out_file, cwd);
