After `git bisect`, found that commit 122bf2997 caused this problem.
@Nicolas, can you fix this commit?


[stardiviner]           <Hack this world!>      GPG key ID: 47C32433
IRC(freeenode): stardiviner                     Twitter:  @numbchild
Key fingerprint = 9BAA 92BC CDDD B9EF 3B36  CB99 B8C4 B8E5 47C3 2433
Blog: http://stardiviner.github.io/

On Sun, Mar 4, 2018 at 9:54 PM, numbchild@gmail.com <numbchild@gmail.com>
wrote:

> With following example:
> ```
> #+begin_src gnuplot :session :results graphics :file "data/images/sin.png"
> :cache no
> set term png
> set grid
> plot sin(x), cos(x)
> #+end_src
> ```
> If I use Org-mode ELPA version. then it works fine.
> But when I use `master` branch version, then it does not have any result.
> Tried to check out git log of recently commits, and `ob-core.el` file
> recent git log commits, and `ob-gnuplot.el`'s. But does not found any
> suspicious commits yet.
>
> Environment info:
> - Arch Linux
> - Emacs version: GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+
> Version 3.22.26) of 2018-02-10
> - Org-mode version: Org mode version 9.1.7 (9.1.7-elpaplus @ mixed
> installation! /home/stardiviner/.emacs.d/elpa/org-plus-contrib-20180226/
> and /home/stardiviner/Code/Emacs/org-mode/lisp/)
>
> [stardiviner]           <Hack this world!>      GPG key ID: 47C32433
> IRC(freeenode): stardiviner                     Twitter:  @numbchild
> Key fingerprint = 9BAA 92BC CDDD B9EF 3B36  CB99 B8C4 B8E5 47C3 2433
> Blog: http://stardiviner.github.io/
>