>From 414e0b3a18abca34bc47f07e55debec0910d4728 Mon Sep 17 00:00:00 2001
From: Juan Manuel Macias <maciaschain@posteo.net>
Date: Fri, 10 Jun 2022 20:12:37 +0200
Subject: [PATCH] lisp/ob-tangle.el: add the `ascii' value to the `comments'
 head. arg.

* (org-babel-tangle-single-block): With the value ascii the comments
are passed as plain text. This is useful for removing all org
metadata from the source file's comments.
---
 lisp/ob-tangle.el | 53 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 17 deletions(-)

diff --git a/lisp/ob-tangle.el b/lisp/ob-tangle.el
index 6685a1599..aed241416 100644
--- a/lisp/ob-tangle.el
+++ b/lisp/ob-tangle.el
@@ -525,23 +525,42 @@ non-nil, return the full association list to be used by
 	      (run-hooks 'org-babel-tangle-body-hook)
 	      (buffer-string))))
 	 (comment
-	  (when (or (string= "both" (cdr (assq :comments params)))
-		    (string= "org" (cdr (assq :comments params))))
-	    ;; From the previous heading or code-block end
-	    (funcall
-	     org-babel-process-comment-text
-	     (buffer-substring
-	      (max (condition-case nil
-		       (save-excursion
-			 (org-back-to-heading t) ; Sets match data
-			 (match-end 0))
-		     (error (point-min)))
-		   (save-excursion
-		     (if (re-search-backward
-			  org-babel-src-block-regexp nil t)
-			 (match-end 0)
-		       (point-min))))
-	      (point)))))
+	  (cond ((or (string= "both" (cdr (assq :comments params)))
+		     (string= "org" (cdr (assq :comments params))))
+		 ;; From the previous heading or code-block end
+		 (funcall
+		  org-babel-process-comment-text
+		  (buffer-substring
+		   (max (condition-case nil
+			    (save-excursion
+			      (org-back-to-heading t) ; Sets match data
+			      (match-end 0))
+			  (error (point-min)))
+			(save-excursion
+			  (if (re-search-backward
+			       org-babel-src-block-regexp nil t)
+			      (match-end 0)
+			    (point-min))))
+		   (point))))
+		((string= "ascii" (cdr (assq :comments params)))
+		 ;; From the previous heading or code-block end
+		 (let ((org-babel-process-comment-text
+			(lambda (str)
+			  (org-export-string-as str 'ascii t))))
+		   (funcall
+		    org-babel-process-comment-text
+		    (buffer-substring
+		     (max (condition-case nil
+			      (save-excursion
+				(org-back-to-heading t) ; Sets match data
+				(match-beginning 0))
+			    (error (point-min)))
+			  (save-excursion
+			    (if (re-search-backward
+				 org-babel-src-block-regexp nil t)
+				(match-beginning 0)
+			      (point-min))))
+		     (point)))))))
          (src-tfile (cdr (assq :tangle params)))
 	 (result
 	  (list start-line
-- 
2.36.1