Backport commit 2267110b6 from Emacs

* lisp/ob-exp.el (org-babel-exp-process-buffer):
* lisp/org-agenda.el (org-agenda-show-new-time):
Always pass an explicit plist to remove-text-properties.

Fix usage of remove-text-properties
2267110b6f00bbb0ad87f4621e6ecd9dc1bd8581
Basil L. Contovounesios
Thu Aug 1 17:04:53 2019 +0300

lisp/ob-exp.el

@@ -281,7 +281,8 @@ this template."
 		    (set-marker begin nil)
 		    (set-marker end nil)))))
 	  (kill-buffer org-babel-exp-reference-buffer)
-	  (remove-text-properties (point-min) (point-max) '(org-reference)))))))
+          (remove-text-properties (point-min) (point-max)
+                                  '(org-reference nil)))))))
 
 (defun org-babel-exp-do-export (info type &optional hash)
   "Return a string with the exported content of a code block.

lisp/org-agenda.el

@@ -9268,7 +9268,7 @@ Called with a universal prefix arg, show the priority instead of setting it."
       (goto-char (point-max))
       (while (not (bobp))
 	(when (equal marker (org-get-at-bol 'org-marker))
-	  (remove-text-properties (point-at-bol) (point-at-eol) '(display))
+          (remove-text-properties (point-at-bol) (point-at-eol) '(display nil))
 	  (org-move-to-column (- (window-width) (length stamp)) t)
           (add-text-properties
 	   (1- (point)) (point-at-eol)