From 62a3fc7538336a196c7049ac9e942bac1563abdb Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Tue, 26 Nov 2013 17:48:47 -0800
Subject: [PATCH] go.tools/go/types: clean up internal iota in all cases

R=dsymonds
CC=golang-dev
https://golang.org/cl/33570043
---
 go/types/resolver.go         | 1 +
 go/types/testdata/const0.src | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/go/types/resolver.go b/go/types/resolver.go
index 15f58ab5..6594334a 100644
--- a/go/types/resolver.go
+++ b/go/types/resolver.go
@@ -661,6 +661,7 @@ func (check *checker) constDecl(obj *Const, typ, init ast.Expr) {
 		if !isConstType(t) {
 			check.errorf(typ.Pos(), "invalid constant type %s", t)
 			obj.typ = Typ[Invalid]
+			check.iota = nil
 			return
 		}
 		obj.typ = t
diff --git a/go/types/testdata/const0.src b/go/types/testdata/const0.src
index b39151dd..7dd58c02 100644
--- a/go/types/testdata/const0.src
+++ b/go/types/testdata/const0.src
@@ -13,6 +13,11 @@ const c0 = x /* ERROR "not constant" */
 // typed constants must have constant types
 const _ interface /* ERROR invalid constant type */ {} = 0
 
+func _ () {
+	const _ interface /* ERROR invalid constant type */ {} = 0
+	for i := 0; i < 10; i++ {} // don't crash with non-nil iota here
+}
+
 // untyped constants
 const (
 	// boolean values