org-element-org-data-parser: Fix when invoked from indirect buffer

* lisp/org-element.el (org-element-org-data-parser): Consider base
buffer file name when calculating Org buffer category.

lisp/org-element.el

@@ -1276,9 +1276,16 @@ parser (e.g. `:end' and :END:).  Return value is a plist."
                               (min robust-end (point))))
                            (+ 2 contents-begin))))
           (category (cond ((null org-category)
-		           (when buffer-file-name
+		           (when (with-current-buffer
+                                     (or (buffer-base-buffer)
+                                         (current-buffer))
+                                   buffer-file-name)
 		             (file-name-sans-extension
-		              (file-name-nondirectory buffer-file-name))))
+		              (file-name-nondirectory
+                               (with-current-buffer
+                                   (or (buffer-base-buffer)
+                                       (current-buffer))
+                                 buffer-file-name)))))
 		          ((symbolp org-category) (symbol-name org-category))
 		          (t org-category)))
           (category (catch 'buffer-category