ox: Ignore INCLUDE keywords in commented headlines

* lisp/ox.el (org-export-expand-include-keyword): Ignore INCLUDE
  keywords in commented headlines.
* testing/lisp/test-ox.el (test-org-export/expand-include): Add test.

etc/ORG-NEWS

@@ -313,6 +313,7 @@ you use "/!" markup when filtering TODO keywords.
 This variable is a ~defcustom~ and replaces the variable
 ~org-babel-capitalize-example-region-markers~, which is a ~defvar~ and
 is now obselete.
+*** =INCLUDE= keywords in commented trees are now ignored.
 
 * Version 9.0
 

lisp/ox.el

@@ -3281,116 +3281,119 @@ storing and resolving footnotes.  It is created automatically."
     ;; Expand INCLUDE keywords.
     (goto-char (point-min))
     (while (re-search-forward include-re nil t)
-      (let ((element (save-match-data (org-element-at-point))))
-	(when (eq (org-element-type element) 'keyword)
-	  (beginning-of-line)
-	  ;; Extract arguments from keyword's value.
-	  (let* ((value (org-element-property :value element))
-		 (ind (org-get-indentation))
-		 location
-		 (file
-		  (and (string-match
-			"^\\(\".+?\"\\|\\S-+\\)\\(?:\\s-+\\|$\\)" value)
-		       (prog1
-			   (save-match-data
-			     (let ((matched (match-string 1 value)))
-			       (when (string-match "\\(::\\(.*?\\)\\)\"?\\'"
-						   matched)
-				 (setq location (match-string 2 matched))
-				 (setq matched
-				       (replace-match "" nil nil matched 1)))
-			       (expand-file-name
-				(org-unbracket-string "\"" "\"" matched)
-				dir)))
-			 (setq value (replace-match "" nil nil value)))))
-		 (only-contents
-		  (and (string-match ":only-contents *\\([^: \r\t\n]\\S-*\\)?"
-				     value)
-		       (prog1 (org-not-nil (match-string 1 value))
-			 (setq value (replace-match "" nil nil value)))))
-		 (lines
-		  (and (string-match
-			":lines +\"\\(\\(?:[0-9]+\\)?-\\(?:[0-9]+\\)?\\)\""
-			value)
-		       (prog1 (match-string 1 value)
-			 (setq value (replace-match "" nil nil value)))))
-		 (env (cond
-		       ((string-match "\\<example\\>" value) 'literal)
-		       ((string-match "\\<export\\(?: +\\(.*\\)\\)?" value)
-			'literal)
-		       ((string-match "\\<src\\(?: +\\(.*\\)\\)?" value)
-			'literal)))
-		 ;; Minimal level of included file defaults to the child
-		 ;; level of the current headline, if any, or one.  It
-		 ;; only applies is the file is meant to be included as
-		 ;; an Org one.
-		 (minlevel
-		  (and (not env)
-		       (if (string-match ":minlevel +\\([0-9]+\\)" value)
-			   (prog1 (string-to-number (match-string 1 value))
-			     (setq value (replace-match "" nil nil value)))
-			 (get-text-property (point)
-					    :org-include-induced-level))))
-		 (args (and (eq env 'literal) (match-string 1 value)))
-		 (block (and (string-match "\\<\\(\\S-+\\)\\>" value)
-			     (match-string 1 value))))
-	    ;; Remove keyword.
-	    (delete-region (point) (line-beginning-position 2))
-	    (cond
-	     ((not file) nil)
-	     ((not (file-readable-p file))
-	      (error "Cannot include file %s" file))
-	     ;; Check if files has already been parsed.  Look after
-	     ;; inclusion lines too, as different parts of the same file
-	     ;; can be included too.
-	     ((member (list file lines) included)
-	      (error "Recursive file inclusion: %s" file))
-	     (t
+      (unless (org-in-commented-heading-p)
+	(let ((element (save-match-data (org-element-at-point))))
+	  (when (eq (org-element-type element) 'keyword)
+	    (beginning-of-line)
+	    ;; Extract arguments from keyword's value.
+	    (let* ((value (org-element-property :value element))
+		   (ind (org-get-indentation))
+		   location
+		   (file
+		    (and (string-match
+			  "^\\(\".+?\"\\|\\S-+\\)\\(?:\\s-+\\|$\\)" value)
+			 (prog1
+			     (save-match-data
+			       (let ((matched (match-string 1 value)))
+				 (when (string-match "\\(::\\(.*?\\)\\)\"?\\'"
+						     matched)
+				   (setq location (match-string 2 matched))
+				   (setq matched
+					 (replace-match "" nil nil matched 1)))
+				 (expand-file-name
+				  (org-unbracket-string "\"" "\"" matched)
+				  dir)))
+			   (setq value (replace-match "" nil nil value)))))
+		   (only-contents
+		    (and (string-match ":only-contents *\\([^: \r\t\n]\\S-*\\)?"
+				       value)
+			 (prog1 (org-not-nil (match-string 1 value))
+			   (setq value (replace-match "" nil nil value)))))
+		   (lines
+		    (and (string-match
+			  ":lines +\"\\(\\(?:[0-9]+\\)?-\\(?:[0-9]+\\)?\\)\""
+			  value)
+			 (prog1 (match-string 1 value)
+			   (setq value (replace-match "" nil nil value)))))
+		   (env (cond
+			 ((string-match "\\<example\\>" value) 'literal)
+			 ((string-match "\\<export\\(?: +\\(.*\\)\\)?" value)
+			  'literal)
+			 ((string-match "\\<src\\(?: +\\(.*\\)\\)?" value)
+			  'literal)))
+		   ;; Minimal level of included file defaults to the
+		   ;; child level of the current headline, if any, or
+		   ;; one.  It only applies is the file is meant to be
+		   ;; included as an Org one.
+		   (minlevel
+		    (and (not env)
+			 (if (string-match ":minlevel +\\([0-9]+\\)" value)
+			     (prog1 (string-to-number (match-string 1 value))
+			       (setq value (replace-match "" nil nil value)))
+			   (get-text-property (point)
+					      :org-include-induced-level))))
+		   (args (and (eq env 'literal) (match-string 1 value)))
+		   (block (and (string-match "\\<\\(\\S-+\\)\\>" value)
+			       (match-string 1 value))))
+	      ;; Remove keyword.
+	      (delete-region (point) (line-beginning-position 2))
 	      (cond
-	       ((eq env 'literal)
-		(insert
-		 (let ((ind-str (make-string ind ?\s))
-		       (arg-str (if (stringp args) (format " %s" args) ""))
-		       (contents
-			(org-escape-code-in-string
-			 (org-export--prepare-file-contents file lines))))
-		   (format "%s#+BEGIN_%s%s\n%s%s#+END_%s\n"
-			   ind-str block arg-str contents ind-str block))))
-	       ((stringp block)
-		(insert
-		 (let ((ind-str (make-string ind ?\s))
-		       (contents
-			(org-export--prepare-file-contents file lines)))
-		   (format "%s#+BEGIN_%s\n%s%s#+END_%s\n"
-			   ind-str block contents ind-str block))))
+	       ((not file) nil)
+	       ((not (file-readable-p file))
+		(error "Cannot include file %s" file))
+	       ;; Check if files has already been parsed.  Look after
+	       ;; inclusion lines too, as different parts of the same
+	       ;; file can be included too.
+	       ((member (list file lines) included)
+		(error "Recursive file inclusion: %s" file))
 	       (t
-		(insert
-		 (with-temp-buffer
-		   (let ((org-inhibit-startup t)
-			 (lines
-			  (if location
-			      (org-export--inclusion-absolute-lines
-			       file location only-contents lines)
-			    lines)))
-		     (org-mode)
-                     (insert
-		      (org-export--prepare-file-contents
-		       file lines ind minlevel
-		       (or (gethash file file-prefix)
-			   (puthash file (cl-incf current-prefix) file-prefix))
-		       footnotes)))
-		   (org-export-expand-include-keyword
-		    (cons (list file lines) included)
-		    (file-name-directory file)
-		    footnotes)
-		   (buffer-string)))))
-	      ;; Expand footnotes after all files have been included.
-	      ;; Footnotes are stored at end of buffer.
-	      (unless included
-		(org-with-wide-buffer
-		 (goto-char (point-max))
-		 (maphash (lambda (k v) (insert (format "\n[fn:%s] %s\n" k v)))
-			  footnotes)))))))))))
+		(cond
+		 ((eq env 'literal)
+		  (insert
+		   (let ((ind-str (make-string ind ?\s))
+			 (arg-str (if (stringp args) (format " %s" args) ""))
+			 (contents
+			  (org-escape-code-in-string
+			   (org-export--prepare-file-contents file lines))))
+		     (format "%s#+BEGIN_%s%s\n%s%s#+END_%s\n"
+			     ind-str block arg-str contents ind-str block))))
+		 ((stringp block)
+		  (insert
+		   (let ((ind-str (make-string ind ?\s))
+			 (contents
+			  (org-export--prepare-file-contents file lines)))
+		     (format "%s#+BEGIN_%s\n%s%s#+END_%s\n"
+			     ind-str block contents ind-str block))))
+		 (t
+		  (insert
+		   (with-temp-buffer
+		     (let ((org-inhibit-startup t)
+			   (lines
+			    (if location
+				(org-export--inclusion-absolute-lines
+				 file location only-contents lines)
+			      lines)))
+		       (org-mode)
+		       (insert
+			(org-export--prepare-file-contents
+			 file lines ind minlevel
+			 (or
+			  (gethash file file-prefix)
+			  (puthash file (cl-incf current-prefix) file-prefix))
+			 footnotes)))
+		     (org-export-expand-include-keyword
+		      (cons (list file lines) included)
+		      (file-name-directory file)
+		      footnotes)
+		     (buffer-string)))))
+		;; Expand footnotes after all files have been
+		;; included.  Footnotes are stored at end of buffer.
+		(unless included
+		  (org-with-wide-buffer
+		   (goto-char (point-max))
+		   (maphash (lambda (k v)
+			      (insert (format "\n[fn:%s] %s\n" k v)))
+			    footnotes))))))))))))
 
 (defun org-export--inclusion-absolute-lines (file location only-contents lines)
   "Resolve absolute lines for an included file with file-link.

testing/lisp/test-ox.el

@@ -1055,6 +1055,11 @@ Text"
   (should-error
    (org-test-with-temp-text "#+INCLUDE: dummy.org"
      (org-export-expand-include-keyword)))
+  ;; Refuse to expand keywords in commented headings.
+  (should
+   (org-test-with-temp-text "* COMMENT H1\n#+INCLUDE: dummy.org"
+     (org-export-expand-include-keyword)
+     t))
   ;; Full insertion with recursive inclusion.
   (should
    (equal
@@ -1262,15 +1267,15 @@ Footnotes[fn:2], foot[fn:test] and [fn:inline:inline footnote]
   ;; Adjacent INCLUDE-keywords should have the same :minlevel if unspecified.
   (should
    (cl-every (lambda (level) (zerop (1- level)))
-	      (org-test-with-temp-text
-		  (concat
-		   (format "#+INCLUDE: \"%s/examples/include.org::#ah\"\n"
-			   org-test-dir)
-		   (format "#+INCLUDE: \"%s/examples/include.org::*Heading\""
-			   org-test-dir))
-		(org-export-expand-include-keyword)
-		(org-element-map (org-element-parse-buffer) 'headline
-		  (lambda (head) (org-element-property :level head))))))
+	     (org-test-with-temp-text
+		 (concat
+		  (format "#+INCLUDE: \"%s/examples/include.org::#ah\"\n"
+			  org-test-dir)
+		  (format "#+INCLUDE: \"%s/examples/include.org::*Heading\""
+			  org-test-dir))
+	       (org-export-expand-include-keyword)
+	       (org-element-map (org-element-parse-buffer) 'headline
+		 (lambda (head) (org-element-property :level head))))))
   ;; INCLUDE does not insert induced :minlevel for src-blocks.
   (should-not
    (equal