h:    &Header{PAXRecords: map[string]string{"GOLANG.x": strings.Repeat("a", maxSpecialFileSize)}},
	}} {
		w := NewWriter(io.Discard)
		if err := w.WriteHeader(test.h); err != ErrFieldTooLong {
			t.Errorf("%v: w.WriteHeader() = %v, want ErrFieldTooLong", test.name, err)
		}
	}
}

// testNonEmptyWriter wraps an io.Writer and ensures that
// Write is never called with an empty buffer.

			},
			Format: FormatPAX,
		}},
	}, {
		file: "testdata/pax-bad-hdr-file.tar",
		err:  ErrHeader,
	}, {
		file: "testdata/pax-bad-hdr-large.tar.bz2",
		err:  ErrFieldTooLong,
	}, {
		file: "testdata/pax-bad-mtime-file.tar",
		err:  ErrHeader,
	}, {
		file: "testdata/pax-pos-size-file.tar",
		headers: []*Header{{
			Name:     "foo",
			Mode:     0640,