Revert "ob-R.el: Improve the capturing of output-type results in sessions."

This reverts commit b51746332dca87a35c387b2db0bb678b4c24a4da.

lisp/ob-R.el

@@ -365,7 +365,7 @@ last statement in BODY, as elisp."
 (defvar ess-eval-visibly-p)
 
 (defun org-babel-R-evaluate-session
-    (session body result-type result-params column-names-p row-names-p)
+  (session body result-type result-params column-names-p row-names-p)
   "Evaluate BODY in SESSION.
 If RESULT-TYPE equals 'output then return standard output as a
 string.  If RESULT-TYPE equals 'value then return the value of the
@@ -395,20 +395,23 @@ last statement in BODY, as elisp."
 	  (org-babel-import-elisp-from-file tmp-file '(16)))
 	column-names-p)))
     (output
-     (let* ((output-file (org-babel-temp-file "R-"))
-	    (sentinel-file (concat output-file "-sentinel")))
-       (org-babel-comint-eval-invisibly-and-wait-for-file
-	session sentinel-file
-	(format "capture.output({%s}, file=%S); file.create(%S)"
-		(org-babel-chomp body)
-		output-file
-		sentinel-file))
-       (with-temp-buffer
-	 (insert-file-contents output-file)
-	 (goto-char (point-min))
-	 (flush-lines "^$")
-	 (delete-trailing-whitespace)
-	 (buffer-string))))))
+     (mapconcat
+      'org-babel-chomp
+      (butlast
+       (delq nil
+	     (mapcar
+	      (lambda (line) (when (> (length line) 0) line))
+	      (mapcar
+	       (lambda (line) ;; cleanup extra prompts left in output
+		 (if (string-match
+		      "^\\([ ]*[>+\\.][ ]?\\)+\\([[0-9]+\\|[ ]\\)" line)
+		     (substring line (match-end 1))
+		   line))
+	       (org-babel-comint-with-output (session org-babel-R-eoe-output)
+		 (insert (mapconcat 'org-babel-chomp
+				    (list body org-babel-R-eoe-indicator)
+				    "\n"))
+		 (inferior-ess-send-input)))))) "\n"))))
 
 (defun org-babel-R-process-value-result (result column-names-p)
   "R-specific processing of return value.