The following sequence of commands: make vanilla M-x org-mode RET M-x erase-buffer RET SPC M-: (setq org-adapt-indentation 'headline-data) M-x org-indent-line RET
results in: Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil) org-indent-line() funcall-interactively(org-indent-line) command-execute(org-indent-line record) execute-extended-command(nil "org-indent-line" "org-indent-li") funcall-interactively(execute-extended-command nil "org-indent-line" "org-indent-li") command-execute(execute-extended-command) `org-indent-line' probably should test ELEMENT on nil-ness, but I'm not sure where exactly. Emacs : GNU Emacs 28.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.38, cairo version 1.16.0) of 2024-06-25, modified by Debian Package: Org mode version 9.8-pre (release_9.7.6-107-gf21415 @ /home/jschmidt/work/org-mode/lisp/)