'error' event should be handled

[nicokaiser]

In WebSocketServer.js, strange errors occur:

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: This socket is closed.
    at Socket._write (net.js:474:19)
    at Socket.write (net.js:466:15)
    at WebSocketServer.<anonymous> (/opt/services/webpush/support/webpush-engine/node_modules/ws/lib/WebSocketServer.js:297:16)
    at /opt/services/webpush/support/webpush-engine/node_modules/ws/lib/WebSocketServer.js:326:25
    at WebSocketServer.handleHixieUpgrade (/opt/services/webpush/support/webpush-engine/node_modules/ws/lib/WebSocketServer.js:372:3)
    at WebSocketServer.handleUpgrade (/opt/services/webpush/support/webpush-engine/node_modules/ws/lib/WebSocketServer.js:147:61)
    at Server.handleUpgrade (/opt/services/webpush/support/webpush-engine/lib/server.js:66:11)
    at Server.<anonymous> (/opt/services/webpush/support/webpush-engine/lib/webpush-engine.js:47:12)
    at Server.emit (events.js:88:20)
    at Socket.<anonymous> (http.js:1425:14)

At the time the 'write' happens, there is no 'error' handler for the socket, that may be why the exception is not caught by the try/catch.

[nicokaiser]

... maybe registering an error handler in 'handleUpgrade' solves the problem of the various "socket.end" calls crashing the server when clients unexpectedly close the connection.

[einaros]

Moving this discussion to the pull req you sent :)