From 9be0b38f5b87c386812ee70c63a3bfbf27f128ee Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Tue, 14 Oct 2014 12:55:46 -0700
Subject: [PATCH] cmd/vet: don't panic if import fails Initializing the unused
 variable formatterType (it will be used soon) was panicking if the import
 couldn't be done, but vet shouldn't be so fragile.

LGTM=gri
R=gri
CC=dsymonds, golang-codereviews
https://golang.org/cl/153480044
---
 cmd/vet/types.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/cmd/vet/types.go b/cmd/vet/types.go
index 5c9fc89a..45c20b03 100644
--- a/cmd/vet/types.go
+++ b/cmd/vet/types.go
@@ -20,10 +20,17 @@ var imports = make(map[string]*types.Package)
 var (
 	stringerMethodType = types.New("func() string")
 	errorType          = types.New("error").Underlying().(*types.Interface)
-	stringerType       = importType("fmt", "Stringer").Underlying().(*types.Interface)
-	formatterType      = importType("fmt", "Formatter").Underlying().(*types.Interface)
+	stringerType       = types.New("interface{ String() string }").(*types.Interface)
+	formatterType      *types.Interface
 )
 
+func init() {
+	typ := importType("fmt", "Formatter")
+	if typ != nil {
+		formatterType = typ.Underlying().(*types.Interface)
+	}
+}
+
 // importType returns the type denoted by the qualified identifier
 // path.name, and adds the respective package to the imports map
 // as a side effect.