if err := r.UnreadByte(); err == nil {
			t.Errorf("n = %d: expected error on UnreadByte", n)
		}
	}
}

func TestUnreadByteOthers(t *testing.T) {
	// A list of readers to use in conjunction with UnreadByte.
	var readers = []func(*Reader, byte) ([]byte, error){
		(*Reader).ReadBytes,
		(*Reader).ReadSlice,
		func(r *Reader, delim byte) ([]byte, error) {
			data, err := r.ReadString(delim)

			panic(err)
		}
		b, err = io.ReadAll(f)
		if err != nil {
			panic(err)
		}
	}
	return bytes.NewReader(b), int64(len(b))
}

func TestIssue8186(t *testing.T) {
	// Directory headers & data found in the TOC of a JAR file.
	dirEnts := []string{

			// Otherwise one bad and unneeded field in an otherwise okay struct
			// makes the whole program not compile. Much of the time these
			// structs are in system headers that cannot be corrected.
			continue
		}

		// Round off up to talign, assumed to be a power of 2.
		off = (off + talign - 1) &^ (talign - 1)

		if f.ByteOffset > off {