From e5636d6e276089f840a282e3ed8ddf77188e6439 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 11 Nov 2009 22:20:05 -0800
Subject: [PATCH] avoid seg fault when return type is unknown

Fixes #80.

R=ken
https://golang.org/cl/154079
---
 src/cmd/gc/subr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 35a3a2f951..75ece477d2 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -1138,6 +1138,11 @@ Tpretty(Fmt *fp, Type *t)
 			break;
 		case 1:
 			t1 = getoutargx(t)->type;
+			if(t1 == T) {
+				// failure to typecheck earlier; don't know the type
+				fmtprint(fp, " ?unknown-type?");
+				break;
+			}
 			if(t1->etype != TFIELD && t1->etype != TFUNC) {
 				fmtprint(fp, " %T", t1);
 				break;
-- 
2.50.0