bug#50218: 28.0.50; org-babel-tangle-file tangles code blocks starting with #+begin_src :tangle no

[Ihor Radchenko <yantar92@posteo.net>]

Tassilo Neubauer <tassilo.neubauer@gmail.com> writes:

> Here are the steps that led to code blocks being tangled I did not 
> expect to:
>
> emacs -Q
> C-x C-h: ~/org-roam/example.org
> content of example.org (excluding "):
> "
> #+begin_src emacs-lisp
> (setq some-emacs-lisp-variable t)
> #+end_src
>
> #+begin_src :tangle no
> ;;This line should not be in the elisp code
> #+end_src
> "
>
> open scratch buffer through menu.
> type into scratch buffer:
> (org-bable-tangle-file "/home/tassilo/org-roam/example.org"
> "/home/tassilo/org-roam/example.el")
> M-x:emacs-lisp-mode
> Select (with mouse) the above line and evaluate region through menu.
> I see in the minibuffer: "Tangled 2 code blocks from example.org"
> After typing C-h C-f: ~/org-roam/example.el
> I see the file content of "example.el" (excluding "):
> "
> (setq some-emacs-lisp-variable t)
>
> ;;This line should not be in the elisp code
>
> "

Well. I can see why you did not expect this, but the real cause is a
typo in your code block.

#+begin_src :tangle no
;;This line should not be in the elisp code
#+end_src

is viewed by Org mode as src block written in ":tangle" programming
language :) That's because you forgot to put language in the block and
Org takes the first word after #+begin_src and the language name.

This block does not have :tangle attribute and thus "example.el"
supplied in your function call is being used :)

On Org side, we may catch such scenarios in org-lint.
M-x org-lint currently reports no problem with the above block.

Not urgent fix. Patches are welcome :)

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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