From f8bb41461599c359b7a95f056f61f0b5657dcffc Mon Sep 17 00:00:00 2001
From: Ihor Radchenko <yantar92@gmail.com>
Date: Thu, 21 Apr 2022 17:34:06 +0800
Subject: [PATCH] org-at-timestamp-p: Fix compatibility with Emacs 26

* lisp/org.el (org-at-timestamp-p): Do not use variables in regexp rx
form.  They are not yet supported in Emacs 26.  Expand them at runtime
instead.
---
 lisp/org.el | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lisp/org.el b/lisp/org.el
index 1fc4251a3..e0144605b 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -15026,8 +15026,9 @@ When matching, the match groups are the following:
   (let* ((regexp
           (if extended
               (if (eq extended 'agenda)
-                  (rx (or (regexp org-ts-regexp3)
-                          (regexp org-element--timestamp-regexp)))
+                  (rx-to-string
+                   `(or (regexp ,org-ts-regexp3)
+                        (regexp ,org-element--timestamp-regexp)))
 		org-ts-regexp3)
             org-ts-regexp2))
 	 (pos (point))