Hello Nikolay Kudryavtsev ! thanks for your interest in this little problem.

I do think it is the same problem. I think that emacs tries to erase the
sql prompt from the response and fails to do it. I'm getting the same
problem that OP describes, when I open an interactive sql buffer and try to
execute anything emacs answers with the error "Wrong type argument:
stringp, nil" and no clue of the actual data. The moment in which I decided
to report the bug might be while executing an stored procedure that doesn't
exist, but this problem shows every time I execute ANYTHING, even a simple
"select 1\ngo\n". You can see by your self that the "Wrong type argument"
error is in the emacs output in my mail.

To tell you the truth I did find a little workaround, that's why I didn't
bother with the problem to much. This bug is in my "todo" list but I'm a
little bussy to try to understand it and make a proper repair. What I did
to workaround it using the ideas provided in the mail of the OP and
watching what was happening in edebug, was to modify sql-product-alist in
sql.el, the "prompt-cont-regexp" in the "ms" product was not even there, so
I put the property and set it to " " ( <- a blank space) and that did the
trick. It now shows the results but when showing those ms-sql-server
results it always eats some spaces in the first column making the rows and
the head of the rows misaligned.

Also as OP said I didn't had this problem in the previous version (24.5)
either.

I'm using osql, and I'm already using cp850 with it, I think that's the
right encoding I should use because its what the command prompt of windows
is using. Why do you think I should use cp866.

Thanks again! I hope this information helps.


2017-05-29 12:52 GMT-04:00 Nikolay Kudryavtsev <
nikolay.kudryavtsev@gmail.com>:

> Hello, Pablo.
>
> I don't think you have the same bug as OP.
>
> In your case it seems that you're trying to execute some stored procedure
> that does not exist and Emacs fails at parsing the reply.
>
> Can you try adding:
>
> (add-to-list 'process-coding-system-alist '("sqlcmd" . cp866))
>
> to your init and see if anything changes. Also, you're using sqlcmd, right?
>
> --
> Best Regards,
> Nikolay Kudryavtsev
>
>