[BUG] org-babel-tangle may fail due to (org-babel-tangle-collect-blocks lang-re tangle-file) [9.6.9 ( @ /home/andrea/.emacs.d/elpa/org-9.6.9/)]

[Andrea <andrea-dev@hotmail.com>]

Hello, thanks for maintaining the great Org Mode!

I have been keeping a literate Org Mode configuration for my init file.
This means that I have tons of src blocks looking like

#+begin_src emacs-lisp :tangle yes
...
#+end_src

Sometimes I get an error on org-babel-load-file saying that
org-babel-tangle-collect-blocks was called with target-file set to nil.

Not totally sure if this is had something to do with my configuration, I
always solved this by adding some spaces before my blocks (it doesn't
make sense, but strangely tended to work).

Since that seems an effective but senseless action, I just looked into it and there is
something weird in the code of org-babel-tangle:

Given the header of the function:

  (defun org-babel-tangle (&optional arg target-file lang-re)

and the docstring section

  "Optional argument TARGET-FILE can be used to specify a default export
  file for all source blocks.  "

I think this let binding in org-babel-tangle is weird and the cause of my error:

  (tangle-file
	     (when (equal arg '(16))
	       (or (cdr (assq :tangle (nth 2 (org-babel-get-src-block-info 'no-eval))))
		   (user-error "Point is not in a source code block"))))

Shouldn't that be:

  (tangle-file
	     (or
               (when (equal arg '(16))
	         (or (cdr (assq :tangle (nth 2 (org-babel-get-src-block-info 'no-eval))))
	             (user-error "Point is not in a source code
	     block")))
             target-file ;; the target file which was passed as input of org-babel-tangle
             ))

With that my problem seems resolved. I think that code is weird because
using a when clause causes a possible nil value for that binding. But we
may still use the target-file input to save the day, no?

Any chance I found a bug?

Best,

Andrea

Emacs  : GNU Emacs 28.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.33, cairo version 1.16.0)
 of 2022-05-31
Package: Org mode version 9.6.9 ( @ /home/andrea/.emacs.d/elpa/org-9.6.9/)