null reference in cleanup deflate

[beatjoerg]

I randomly get this error:

TypeError: Cannot read property 'close' of null
at InflateRaw.Zlib.close (zlib.js:469:15)
at PerMessageDeflate.cleanup (ws/lib/PerMessageDeflate.js:82:46)

Can someone have a look at this issue. It looks to me, that something that is already closed get closed again...

[darrachequesne]

Weird, there must be some kind of race condition here (with https://github.com/websockets/ws/blob/master/lib/PerMessageDeflate.js#L259), since this._inflate is checked against null value just before:

PerMessageDeflate.prototype.cleanup = function() {
  if (this._inflate) {
    if (this._inflate.writeInProgress) {
      this._inflate.pendingClose = true;
    } else {
      if (this._inflate.close) this._inflate.close(); //L82
      this._inflate = null;
    }
  }
  ...

One quick fix would be to catch any exception here https://github.com/websockets/ws/blob/master/lib/WebSocket.js#L956

if (this.extensions[PerMessageDeflate.extensionName]) {
  try {
    this.extensions[PerMessageDeflate.extensionName].cleanup(); }
  catch (e) {}
}

[headlessme]

I'm seeing the same issue

TypeError: Cannot read property 'close' of null
    at InflateRaw.Zlib.close (zlib.js:465:15)
    at PerMessageDeflate.cleanup (/var/app/current/node_modules/ws/lib/PerMessageDeflate.js:82:46)
    at WebSocket.cleanupWebsocketResources (/var/app/current/node_modules/ws/lib/WebSocket.js:957:54)
    at emitNone (events.js:72:20)
    at Socket.emit (events.js:166:7)
    at endReadableNT (_stream_readable.js:905:12)
    at nextTickCallbackWith2Args (node.js:441:9)
    at process._tickDomainCallback (node.js:396:17)

[headlessme]

Looks like this might actually be a problem with zlib:

var zlib = require('zlib');
var inflate = zlib.createInflateRaw(15);
inflate.on('error', function(e) {  });
inflate.write('something invalid');
setTimeout(function(){
    inflate.close();  
}, 100);

output:

$ node inflate-close.js 
zlib.js:465
  this._handle.close();
              ^

TypeError: Cannot read property 'close' of null
    at InflateRaw.Zlib.close (zlib.js:465:15)
    at null._onTimeout (/tmp/inflate-close.js:8:13)
    at Timer.listOnTimeout (timers.js:92:15)