2015-10-14 0:18 GMT+02:00 Nicolas Goaziou <mail@nicolasgoaziou.fr>:

> Fabrice Popineau <fabrice.popineau@gmail.com> writes:
>
> > This is a pity. Things would be more straightforward.
>
> Straightforward for what? Use againframes? Or force label?
>
>
Force label. Having to explicitly state it twice :

  * Frame 1
  :PROPERTIES:
  :CUSTOM_ID: foo
  :BEAMER_opt: label=foo
  :END:

is not exactly straightforward. The following (crude) patch would avoid it.

Anyway, the BEAMER_opt label= way of setting the label is not Org-y.

Regards,

Fabrice

diff --git a/vendor/org-mode/lisp/ox-beamer.el
b/vendor/org-mode/lisp/ox-beamer.el
index 24dcf19..cc8d241 100644
--- a/vendor/org-mode/lisp/ox-beamer.el
+++ b/vendor/org-mode/lisp/ox-beamer.el
@@ -333,11 +333,13 @@ INFO is a plist used as a communication channel.
 The value is either the label specified in \"BEAMER_opt\"
 property, or a fallback value built from headline's number.  This
 function assumes HEADLINE will be treated as a frame."
+  (if org-latex-prefer-user-labels
+      (org-element-property :CUSTOM_ID headline)
       (let ((opt (org-element-property :BEAMER_OPT headline)))
        (if (and (stringp opt)
                 (string-match "\\(?:^\\|,\\)label=\\(.*?\\)\\(?:$\\|,\\)"
opt))
            (match-string 1 opt)
-      (format "{sec:%s}" (org-export-get-reference headline info)))))
+         (format "{sec:%s}" (org-export-get-reference headline info))))))

 (defun org-beamer--frame-level (headline info)
   "Return frame level in subtree containing HEADLINE.