Notebook saving fails sometime

[tkf]

After the saving failure, you can save it again if you repeat the command "C-x C-s".

This is maybe a bug in Emacs url-retrieve.
See: #11469 - 24.1.50; url-retrieve with PUT method fails every two times - GNU bug report logs

Note: It is possible to implement workaround for this. So maybe I should do it sometime later.

Also maybe related to the issue of url-retrieve, network connection is not closed sometimes (You can see it in the *Process List* buffer).

[tkf]

I already implemented retry and "singleton query" (ein:query-singleton-ajax). Closing this issue as I think they are all I can do in EIN side.