From cb0a00c9e7bd5fab09ce481f07bc589b3f9bf0c0 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Tue, 24 Jan 2017 23:04:33 +0100
Subject: [PATCH] Don't crash trying to dump move hops (with no output value).

---
 mach/proto/mcg/hop.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mach/proto/mcg/hop.c b/mach/proto/mcg/hop.c
index d36fa6fc8..d4884f7a7 100644
--- a/mach/proto/mcg/hop.c
+++ b/mach/proto/mcg/hop.c
@@ -293,7 +293,9 @@ static void appendheader(struct hop* hop)
 {
     int i;
 
-    appendf("$%d.%d", hop->value->ir->id, hop->value->subid);
+    appendf("%d: ", hop->id);
+    if (hop->value)
+        appendf("$%d.%d", hop->value->ir->id, hop->value->subid);
     if (hop->ir)
         appendf(" from $%d", hop->ir->id);
     appendf(":");
-- 
2.34.1