t.Errorf("test %d, NewReader(%s) with %s discard: got %d headers, want %d headers",
					i, s1, s2, cnt, v.cnt)
			}
		}
	}
}

// TestReadHeaderOnly tests that Reader does not attempt to read special
// header-only files.
func TestReadHeaderOnly(t *testing.T) {
	f, err := os.Open("testdata/hdr-only.tar")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer f.Close()