Avoid NULL-pointer deref and for now, simply exit if required terminal

capabilities aren't there. Since the capabilities in question are marked
`obsolete' in termcap(5), someone might want to have another look
at this someday (PR#2417).

diff --git a/snake/snake/move.c b/snake/snake/move.c
index 5a90795d96f8b9d4bc26061ec0907b9d843c5a4f..3a7d61d63fa1c03c75ef114c05317aa492af8ad5 100644 (file)
--- a/snake/snake/move.c
+++ b/snake/snake/move.c
@@ -1,4 +1,4 @@
-/*     $NetBSD: move.c,v 1.11 1995/04/29 01:17:12 mycroft Exp $        */
+/*     $NetBSD: move.c,v 1.12 1996/05/19 20:22:09 pk Exp $     */
 
 /*
  * Copyright (c) 1980, 1993
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)move.c     8.1 (Berkeley) 7/19/93";
 #else
-static char rcsid[] = "$NetBSD: move.c,v 1.11 1995/04/29 01:17:12 mycroft Exp $";
+static char rcsid[] = "$NetBSD: move.c,v 1.12 1996/05/19 20:22:09 pk Exp $";
 #endif
 #endif /* not lint */
 
@@ -642,14 +642,23 @@ getcap()
        if (xPC)
                PC = *xPC;
 
-       NDlength = strlen(ND);
-       BSlength = strlen(BS);
        if ((CM == 0) &&
-               (HO == 0 | UP==0 || BS==0 || ND==0)) {
+               (HO == 0 || UP == 0 || BS == 0 || ND == 0)) {
                fprintf(stderr, "Terminal must have addressible ");
                fprintf(stderr, "cursor or home + 4 local motions\n");
                exit(5);
        }
+       if (ND == 0) {
+               fprintf(stderr, "Terminal must have `nd' capability\n");
+               exit(5);
+       }
+       NDlength = strlen(ND);
+       if (BS == 0) {
+               fprintf(stderr, "Terminal must have `bs' or `bc' capability\n");
+               exit(5);
+       }
+       BSlength = strlen(BS);
+
        if (tgetflag("os")) {
                fprintf(stderr, "Terminal must not overstrike\n");
                exit(5);