* main.c: prevent segmentation faults on inferiour operating systems

such as Debian GNU/Linux "etch" 4.0 with not installed locale file
  corresponding to the current environmental settings. ばかたち!

main.c

@@ -13,7 +13,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.63 2007/01/03 22:43:47 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.64 2007/01/06 17:08:14 tg Exp $");
 
 extern char **environ;
 
@@ -280,16 +280,18 @@ main(int argc, char *argv[])
 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
 	if (Flag(FTALKING)) {
 #if HAVE_SETLOCALE_CTYPE
+#define isuc(x)	(((x) != NULL) && \
+		    (strcasestr((x), "UTF-8") || strcasestr((x), "utf8")))
 		/* Check if we're in a UTF-8 locale */
 		if (!Flag(FUTFHACK)) {
 			cc = setlocale(LC_CTYPE, "");
 #if HAVE_LANGINFO_CODESET
-			if (!strcasestr(cc, "UTF-8") && !strcasestr(cc, "utf8"))
+			if (!isuc(cc))
 				cc = nl_langinfo(CODESET);
 #endif
-			Flag(FUTFHACK) = strcasestr(cc, "UTF-8") ||
-			    strcasestr(cc, "utf8");
+			Flag(FUTFHACK) = isuc(cc);
 		}
+#undef isuc
 #endif
 		x_init();
 	}