b.lastRuneSize = -1
	}

	return
}

// ReadLine is a low-level line-reading primitive. Most callers should use
// [Reader.ReadBytes]('\n') or [Reader.ReadString]('\n') instead or use a [Scanner].
//
// ReadLine tries to return a single line, not including the end-of-line bytes.
// If the line was too long for the buffer then isPrefix is set and the