Backport commit 19f2f2699 from Emacs

* lisp/org-compat.el (org--setup-calendar-bindings): Fix logic
in test of 'org-agenda-diary-file' (bug#48199).

Prevent Org mode from mistakenly changing Calendar keymap
19f2f2699499d87186c6f580e4ec79205d59c096
Stephen Berman
Fri Jun 25 11:11:43 2021 +0200

lisp/org-compat.el

@@ -1146,8 +1146,8 @@ key."
     ((guard (not (lookup-key calendar-mode-map "c")))
      (local-set-key "c" #'org-calendar-goto-agenda))
     (_ nil))
-  (unless (and (boundp 'org-agenda-diary-file)
-	       (eq org-agenda-diary-file 'diary-file))
+  (when (and (boundp 'org-agenda-diary-file)
+	     (not (eq org-agenda-diary-file 'diary-file)))
     (local-set-key org-calendar-insert-diary-entry-key
 		   #'org-agenda-diary-entry)))