[balsa/wip/gmime3] sendmsg-window: Check when replying to a list

[Peter Bloomfield <peterb src gnome org>]

commit b89ce1d78a3f2c3519e4ad37ca52a3cc98ba398e
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Tue May 29 19:08:41 2018 -0400

    sendmsg-window: Check when replying to a list
    
    * src/sendmsg-window.c (sendmsg_window_reply): If the message is
      a reply to a mailing list, check that the message we are
      replying to actually came from a mailing list; if not, return NULL.

 ChangeLog            | 7 +++++++
 src/sendmsg-window.c | 9 +++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 3b41d0243..91d06c48c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2018-05-29  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       * src/sendmsg-window.c (sendmsg_window_reply): If the message is
+       a reply to a mailing list, check that the message we are
+       replying to actually came from a mailing list; if not, return
+       NULL.
+
 2018-05-29  Peter Bloomfield  <pbloomfield bellsouth net>
 
        * src/main-window.c (bw_enable_message_menus): Disable "reply to
diff --git a/src/sendmsg-window.c b/src/sendmsg-window.c
index e75364cdd..f3ec15292 100644
--- a/src/sendmsg-window.c
+++ b/src/sendmsg-window.c
@@ -6771,13 +6771,18 @@ sendmsg_window_reply(LibBalsaMailbox * mailbox, guint msgno,
 {
     LibBalsaMessage *message =
         libbalsa_mailbox_get_message(mailbox, msgno);
-    BalsaSendmsg *bsmsg = sendmsg_window_new();
+    BalsaSendmsg *bsmsg;
 
     g_assert(message);
     switch(reply_type) {
+    case SEND_REPLY_GROUP:
+        if (libbalsa_message_get_user_header(message, "list-post") == NULL) {
+            g_object_unref(message);
+            return NULL;
+        }
     case SEND_REPLY:
     case SEND_REPLY_ALL:
-    case SEND_REPLY_GROUP:
+        bsmsg = sendmsg_window_new();
         bsmsg->type = reply_type;       break;
     default: printf("reply_type: %d\n", reply_type); g_assert_not_reached();
     }