From e626b929e0c89b9a09f83eb20bffbe5a56a5256f Mon Sep 17 00:00:00 2001
From: stardiviner <numbchild@gmail.com>
Date: Tue, 10 Apr 2018 17:44:41 +0800
Subject: [PATCH 2/2] ob-core.el: support graphics :results type.

* lisp/ob-core.el (org-babel-common-header-args-w-values): Add
  "graphics" :results type.

* testing/lisp/test-ob.el (test-ob/result-graphics-link-type-header-argument)
  Add test for "graphics" :results type.

* doc/org-manual.org: add manual for "graphics" :results type.
---
 doc/org-manual.org      | 16 ++++++++++++++++
 lisp/ob-core.el         |  2 +-
 testing/lisp/test-ob.el | 16 ++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/doc/org-manual.org b/doc/org-manual.org
index 3c759d601..4b851e534 100644
--- a/doc/org-manual.org
+++ b/doc/org-manual.org
@@ -17189,6 +17189,22 @@ default behavior is to automatically determine the result type.
      wget -c "http://example.com/download.tar.gz"
      #+end_src
 
+- =graphics= :: 
+
+     #+cindex: @samp{graphics}, header argument
+     When this result type used with header argument =:file=, generate a
+     link to =:file= specified file. Instead of writing src block
+     evaluate non-empty result to =:file= specified file. This will be
+     useful for generating Org inline image for src blocks. Like
+     following example:
+
+     #+begin_src R :results graphics :file "graphics-result.png"
+     plot(seq(1,10))
+     #+end_src
+
+     #+RESULTS:
+     [[file:graphics-result.png]]
+
 *** Format
 :PROPERTIES:
 :UNNUMBERED: notoc
diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index e21cbf963..9c72bbccb 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -416,7 +416,7 @@ then run `org-babel-switch-to-session'."
     (results	. (
 		   ;; separate group to avoid been override by "file"
 		   ;; :results in `org-babel-merge-params'.
-		   (link)
+		   (link graphics)
 		   (file list vector table scalar verbatim)
 		   (raw html latex org code pp drawer)
 		   (replace silent none append prepend)
diff --git a/testing/lisp/test-ob.el b/testing/lisp/test-ob.el
index e541ad726..3b7958552 100644
--- a/testing/lisp/test-ob.el
+++ b/testing/lisp/test-ob.el
@@ -1012,6 +1012,22 @@ echo \"test\"
    	      "hello\n"
    	      (buffer-substring-no-properties (point-min) (point-max)))))))
 
+(ert-deftest test-ob/result-graphics-link-type-header-argument ()
+  "Ensure that the result is a link to an image.
+The file is just a link to :file value. Inhibit non-empty result write to :file."
+(org-test-with-temp-text "#+begin_src shell :results value graphics :file \"/tmp/test.txt\"
+echo \"hello\" > /tmp/test.txt
+echo \"test\"
+#+end_src"
+   (org-babel-execute-src-block)
+   (goto-char (point-min))
+   (should (search-forward "[[file:/tmp/test.txt]]" nil nil))
+   (should (with-temp-buffer
+   	     (insert-file-contents "/tmp/test.txt")
+   	     (string=
+   	      "hello\n"
+   	      (buffer-substring-no-properties (point-min) (point-max)))))))
+
 (ert-deftest test-ob/inline-src_blk-preceded-punct-preceded-by-point ()
   (let ((test-line ".src_emacs-lisp[ :results verbatim ]{ \"x\"  }")
 	(org-babel-inline-result-wrap "=%s="))
-- 
2.17.0