[evolution] I#1640 - prefer-plain: Do not hide attachments

[Milan Crha <mcrha src gnome org>]

commit ee6837bbc7b84d6c84f135c02588b9dea8ad5083
Author: Milan Crha <mcrha redhat com>
Date:   Thu Sep 23 19:25:14 2021 +0200

    I#1640 - prefer-plain: Do not hide attachments
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1640

 src/modules/prefer-plain/e-mail-parser-prefer-plain.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/modules/prefer-plain/e-mail-parser-prefer-plain.c 
b/src/modules/prefer-plain/e-mail-parser-prefer-plain.c
index a2d98f4694..86480ccf02 100644
--- a/src/modules/prefer-plain/e-mail-parser-prefer-plain.c
+++ b/src/modules/prefer-plain/e-mail-parser-prefer-plain.c
@@ -184,7 +184,8 @@ hide_parts (GQueue *work_queue)
        for (link = head; link != NULL; link = g_list_next (link)) {
                EMailPart *mail_part = link->data;
 
-               mail_part->is_hidden = TRUE;
+               if (!e_mail_part_get_is_attachment (mail_part))
+                       mail_part->is_hidden = TRUE;
        }
 }