pkg: fix incorrect prints found by govet

Also, clarify some error messages

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4548042

src/pkg/crypto/openpgp/packet/public_key_test.go

@@ -72,7 +72,7 @@ func TestPublicKeySerialize(t *testing.T) {
 		serializeBuf := bytes.NewBuffer(nil)
 		err = pk.Serialize(serializeBuf)
 		if err != nil {
-			t.Errorf("#%d: failed to serialize: %s", err)
+			t.Errorf("#%d: failed to serialize: %s", i, err)
 			continue
 		}
 

src/pkg/http/request_test.go

@@ -222,13 +222,13 @@ func TestEmptyMultipartRequest(t *testing.T) {
 func testMissingFile(t *testing.T, req *Request) {
 	f, fh, err := req.FormFile("missing")
 	if f != nil {
-		t.Errorf("FormFile file = %q, want nil", f, nil)
+		t.Errorf("FormFile file = %q, want nil", f)
 	}
 	if fh != nil {
-		t.Errorf("FormFile file header = %q, want nil", fh, nil)
+		t.Errorf("FormFile file header = %q, want nil", fh)
 	}
 	if err != ErrMissingFile {
-		t.Errorf("FormFile err = %q, want nil", err, ErrMissingFile)
+		t.Errorf("FormFile err = %q, want ErrMissingFile", err)
 	}
 }
 
@@ -236,7 +236,7 @@ func newTestMultipartRequest(t *testing.T) *Request {
 	b := bytes.NewBufferString(strings.Replace(message, "\n", "\r\n", -1))
 	req, err := NewRequest("POST", "/", b)
 	if err != nil {
-		t.Fatalf("NewRequest:", err)
+		t.Fatal("NewRequest:", err)
 	}
 	ctype := fmt.Sprintf(`multipart/form-data; boundary="%s"`, boundary)
 	req.Header.Set("Content-type", ctype)
@@ -276,7 +276,7 @@ func validateTestMultipartContents(t *testing.T, req *Request, allMem bool) {
 func testMultipartFile(t *testing.T, req *Request, key, expectFilename, expectContent string) multipart.File {
 	f, fh, err := req.FormFile(key)
 	if err != nil {
-		t.Fatalf("FormFile(%q):", key, err)
+		t.Fatalf("FormFile(%q): %q", key, err)
 	}
 	if fh.Filename != expectFilename {
 		t.Errorf("filename = %q, want %q", fh.Filename, expectFilename)

src/pkg/http/response_test.go

@@ -376,7 +376,7 @@ func TestReadResponseCloseInMiddle(t *testing.T) {
 		rest, err := ioutil.ReadAll(bufr)
 		checkErr(err, "ReadAll on remainder")
 		if e, g := "Next Request Here", string(rest); e != g {
-			fatalf("for chunked=%v remainder = %q, expected %q", g, e)
+			fatalf("remainder = %q, expected %q", g, e)
 		}
 	}
 }
@@ -385,7 +385,7 @@ func diff(t *testing.T, prefix string, have, want interface{}) {
 	hv := reflect.ValueOf(have).Elem()
 	wv := reflect.ValueOf(want).Elem()
 	if hv.Type() != wv.Type() {
-		t.Errorf("%s: type mismatch %v vs %v", prefix, hv.Type(), wv.Type())
+		t.Errorf("%s: type mismatch %v want %v", prefix, hv.Type(), wv.Type())
 	}
 	for i := 0; i < hv.NumField(); i++ {
 		hf := hv.Field(i).Interface()

src/pkg/mime/multipart/formdata_test.go

@@ -33,7 +33,7 @@ func TestReadForm(t *testing.T) {
 	}
 	fd = testFile(t, f.File["fileb"][0], "fileb.txt", filebContents)
 	if _, ok := fd.(*os.File); !ok {
-		t.Error("file has unexpected underlying type %T", fd)
+		t.Errorf("file has unexpected underlying type %T", fd)
 	}
 }
 

src/pkg/os/user/user_test.go

@@ -42,7 +42,7 @@ func TestLookup(t *testing.T) {
 	}
 	fi, err := os.Stat(u.HomeDir)
 	if err != nil || !fi.IsDirectory() {
-		t.Errorf("expected a valid HomeDir; stat(%q): err=%v, IsDirectory=%v", err, fi.IsDirectory())
+		t.Errorf("expected a valid HomeDir; stat(%q): err=%v, IsDirectory=%v", u.HomeDir, err, fi.IsDirectory())
 	}
 	if u.Username == "" {
 		t.Fatalf("didn't get a username")