Randomly losing connections under emacs-ipython-notebook with version 1.11 about emacs-websocket

[nnicandro]

I ran into this issue as well. The server I was communicating with was closing the websocket connection due to an invalid frame being sent. It looks like encode-coding-string causes issues if used in websocket-mask that are dependent on the specific byte pattern used for the masking.

Here is a test case that will always fail when encode-coding-string is used in websocket-mask

(cl-letf ((text "{\"parent_header\":{},\"header\":{\"msg_id\":\"a2940bc8-619e-4872-97bd-4c8d6fb93017\",\"msg_type\":\"history_request\",\"version\":\"5.3\",\"username\":\"n\",\"session\":\"409cf442-74ba-462f-8183-6652503005af\",\"date\":\"2019-06-20T02:17:43.925049-0500\"},\"content\":{\"output\":false,\"raw\":false,\"hist_access_type\":\"tail\",\"n\":100},\"metadata\":{},\"buffers\":[],\"channel\":\"shell\"}")
          ((symbol-function #'websocket-genbytes)
           (lambda (&rest _) "\10\206\356\224")))
  (let ((frame (websocket-read-frame
                (websocket-encode-frame
                 (make-websocket-frame :opcode 'text
                                       :payload (encode-coding-string text 'raw-text)
                                       :completep t)
                 t))))
    (should frame)
    (should (equal (websocket-frame-payload frame) text))))

[ahyatt]

I'll see if I can reproduce. None of the commits recently look like they should effect connections at all, although maybe the recent change in error handling behavior caused some hidden problem to surface. Anyway, if I can reproduce it, I'll fix it.

[ahyatt]

According to @dickmao, #59 fixes this issue, which I've merged into head.

Can you confirm this fixes the issue? If so, I'll rev. the version to 1.11.1.

[ahyatt]

I've also made an addition small fix beyond the basic fix @dickmao provided in 37ef222. However, I was never able to reproduce this - any clues how I can try to reproduce this sort of thing in a functional test would help me make sure I don't break you again.

[millejoh]

@ahyatt - thanks for the quick response. Yes, I can confirm that EIN is working again. I wish I were smart enough to come up with a good test case, but hopefully the one @dzop provided will serve as check against this happening again.