// A batch version of this computation is in image/draw/draw.go.

	cr, cg, cb, ca := c.RGBA()
	ret, bestSum := 0, uint32(1<<32-1)
	for i, v := range p {
		vr, vg, vb, va := v.RGBA()
		sum := sqDiff(cr, vr) + sqDiff(cg, vg) + sqDiff(cb, vb) + sqDiff(ca, va)
		if sum < bestSum {
			if sum == 0 {
				return i
			}
			ret, bestSum = i, sum
		}
	}
	return ret
}

		part, err := reader.NextPart()
		if part == nil {
			t.Errorf("Expected a body part on text %d", testNum)
			continue
		}
		if err != nil {
			t.Errorf("Unexpected error on text %d: %v", testNum, err)
			continue
		}
		written, err := io.Copy(buf, part)
		expectEq(t, expectedBody, buf.String(), fmt.Sprintf("test %d", testNum))
		if err != nil {
			t.Errorf("Error copying multipart; bytes=%v, error=%v", written, err)
		}

					panic("AcceptableCAs should have been empty")
				}
				return new(Certificate), nil
			}
		},
		"",
		func(t *testing.T, testNum int, cs *ConnectionState) {
			if l := len(cs.PeerCertificates); l != 0 {
				t.Errorf("#%d: expected no certificates but got %d", testNum, l)
			}
		},
	},
	{
		func(clientConfig, serverConfig *Config) {
			// With TLS 1.1, the SignatureSchemes should be

				// the one that minimizes sum-squared-difference.
				// TODO(nigeltao): consider smarter algorithms.
				bestIndex, bestSum := 0, uint32(1<<32-1)
				for index, p := range palette {
					sum := sqDiff(er, p[0]) + sqDiff(eg, p[1]) + sqDiff(eb, p[2]) + sqDiff(ea, p[3])
					if sum < bestSum {
						bestIndex, bestSum = index, sum
						if sum == 0 {
							break
						}
					}
				}

		accept := req.Header.Get("Accept-Encoding")
		if expect := req.FormValue("expect_accept"); accept != expect {
			t.Errorf("in handler, test %v: Accept-Encoding = %q, want %q",
				req.FormValue("testnum"), accept, expect)
		}
		if accept == "gzip" {
			rw.Header().Set("Content-Encoding", "gzip")
			gz := gzip.NewWriter(rw)
			gz.Write([]byte(responseBody))
			gz.Close()
		} else {