From 0acb63769c900aad6e8d7d4380f248ef40829c0b Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Sat, 11 Sep 2010 15:47:56 -0400
Subject: [PATCH] gc: const nil bug

Fixes #1073.

R=ken2
CC=golang-dev
https://golang.org/cl/2169043
---
 src/cmd/gc/walk.c | 4 ++++
 test/const1.go    | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index e51b750b6c..fc8f19ec13 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -261,6 +261,10 @@ walkdef(Node *n)
 			yyerror("const initializer must be constant");
 			goto ret;
 		}
+		if(isconst(e, CTNIL)) {
+			yyerror("const initializer cannot be nil");
+			goto ret;
+		}
 		t = n->type;
 		if(t != T) {
 			convlit(&e, t);
diff --git a/test/const1.go b/test/const1.go
index 427d61e59c..cf07055cfa 100644
--- a/test/const1.go
+++ b/test/const1.go
@@ -77,3 +77,5 @@ func main() {
 	f(String)	// ERROR "convert|wrong type|cannot|incompatible"
 	f(Bool)	// ERROR "convert|wrong type|cannot|incompatible"
 }
+
+const ptr = nil  // ERROR "const.*nil"
-- 
2.51.0