[balsa] message-window.c: Manage "Reply to Group" action

[Peter Bloomfield <peterb src gnome org>]

commit 506bfc9078f3400162b18131b8861ef15b43d173
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Wed May 30 15:05:23 2018 -0400

    message-window.c: Manage "Reply to Group" action
    
            * src/message-window.c (message_window_new): Disable "reply to
            group" when the message is not from an RFC-2369-compliant
            mailing list.
            <URL:https://tools.ietf.org/html/rfc2369>

 ChangeLog            | 7 +++++++
 src/message-window.c | 3 +++
 2 files changed, 10 insertions(+)
---
diff --git a/ChangeLog b/ChangeLog
index b2a79671a..346811fc6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2018-05-30  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       * src/message-window.c (message_window_new): Disable "reply to
+       group" when the message is not from an RFC-2369-compliant
+       mailing list.
+       <URL:https://tools.ietf.org/html/rfc2369>
+
 2018-05-29  Peter Bloomfield  <pbloomfield bellsouth net>
 
        * src/balsa-index.c (bndx_selection_changed): Emit
diff --git a/src/message-window.c b/src/message-window.c
index d23623704..cb3d5d29d 100644
--- a/src/message-window.c
+++ b/src/message-window.c
@@ -907,6 +907,9 @@ message_window_new(LibBalsaMailbox * mailbox, guint msgno)
     if (!balsa_app.show_message_toolbar)
         gtk_widget_hide(mw->toolbar);
 
+    mw_set_enabled(mw, "reply-group",
+                   libbalsa_message_get_user_header(message, "list-post") != NULL);
+
     gtk_window_set_default_size(GTK_WINDOW(window),
                                 balsa_app.message_window_width, 
                                 balsa_app.message_window_height);