return src.appendSlice(rb.out, p, n)
		}
		if rb.nrune > 0 {
			return doAppendInner(rb, p)
		}
	}
	p = appendQuick(rb, p)
	return doAppendInner(rb, p)
}

func doAppendInner(rb *reorderBuffer, p int) []byte {
	for n := rb.nsrc; p < n; {
		p = decomposeSegment(rb, p, true)
		p = appendQuick(rb, p)
	}
	return rb.out
}

// AppendString returns f(append(out, []byte(s))).