From: Markus Armbruster <armbru@pond.sub.org>
Date: Sun, 27 Dec 2020 11:43:19 +0000 (+0100)
Subject: bomb launch interdiction: Fix crash on bombs missing target
X-Git-Url: http://git.pond.sub.org/?p=empserver;a=commitdiff_plain;h=e312e4f8d6eea49423722c87b7f368e42b1086be

bomb launch interdiction: Fix crash on bombs missing target

plane damage() prints @noisy with snprintf() even when it's null.  It
doesn't actually use the output then.  Some systems (GNU, Windows)
deal gracefully with printing null strings, others crash.  @noisy is
null when bombers or missiles miss and do collateral damage.  Affects
bomb, launch, and interdiction missions.  Broken in commit 820d755e5
"subs: Change pln_damage()'s parameter noisy to string prefix",
v4.3.33.

Fix by guarding the snprintf().

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
---

diff --git a/src/lib/subs/plnsub.c b/src/lib/subs/plnsub.c
index 28653ea68..29c1f9af0 100644
--- a/src/lib/subs/plnsub.c
+++ b/src/lib/subs/plnsub.c
@@ -30,7 +30,7 @@
  *     Dave Pare, 1986
  *     Ken Stevens, 1995
  *     Steve McClure, 1998-2000
- *     Markus Armbruster, 2004-2016
+ *     Markus Armbruster, 2004-2020
  */
 
 #include <config.h>
@@ -1052,7 +1052,7 @@ pln_damage(struct plnstr *pp, char type, char *noisy)
 	aim = 100 - aim;
     }
 
-    len = snprintf(buf, sizeof(buf), "%s", noisy);
+    len = noisy ? snprintf(buf, sizeof(buf), "%s", noisy) : 0;
     while (i--) {
 	if (noisy) {
 	    if (len > 75) {