Fix conversion of text/html->multipart/related

* lisp/gnus/mml.el (mml-expand-all-html-into-multipart-related):
New function (bug#39230).
(mml-generate-mime): Use it to expand all HTML parts, no matter
where in the MIME tree.

1 files changed, 14 insertions, 5 deletions

diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index cdd8f3d3a50..3d86c5bc407 100644
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -487,11 +487,8 @@ type detected."
                  (= (length cont) 1)
                  content-type)
         (setcdr (assq 'type (cdr (car cont))) content-type))
-      (when (and (consp (car cont))
-                 (= (length cont) 1)
-                 (fboundp 'libxml-parse-html-region)
-                 (equal (cdr (assq 'type (car cont))) "text/html"))
-        (setq cont (mml-expand-html-into-multipart-related (car cont))))
+      (when (fboundp 'libxml-parse-html-region)
+        (setq cont (mapcar 'mml-expand-all-html-into-multipart-related cont)))
       (prog1
           (with-temp-buffer
             (set-buffer-multibyte nil)
@@ -510,6 +507,18 @@ type detected."
             (buffer-string))
         (setq message-options options)))))
 
+(defun mml-expand-all-html-into-multipart-related (cont)
+  (cond ((and (eq (car cont) 'part)
+              (equal (cdr (assq 'type cont)) "text/html"))
+         (mml-expand-html-into-multipart-related cont))
+        ((eq (car cont) 'multipart)
+         (let ((cur (cdr cont)))
+           (while (consp cur)
+             (setcar cur (mml-expand-all-html-into-multipart-related (car cur)))
+             (setf cur (cdr cur))))
+         cont)
+        (t cont)))
+
 (defun mml-expand-html-into-multipart-related (cont)
   (let ((new-parts nil)
         (cid 1))