Don't let a code literal get modified in mml parsing (Bug#39884)

* lisp/gnus/mml.el (mml-parse-1): Make a fresh cons for the tag type,
because 'mml-generate-mime' destructively modifies it.

diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index cdd8f3d3a50610e42f5566f2c8b009af2698bd48..556cf0804a570730e2abefbbe71f255817007fad 100644 (file)
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -281,7 +281,7 @@ part.  This is for the internal use, you should never modify the value.")
            (setq tag (mml-read-tag)
                  no-markup-p nil
                  warn nil)
-         (setq tag (list 'part '(type . "text/plain"))
+         (setq tag (list 'part (cons 'type "text/plain"))
                no-markup-p t
                warn t))
        (setq raw (cdr (assq 'raw tag))