[evolution-data-server] Check for the presence of message id.

[Chenthill Palanisamy <pchen src gnome org>]

commit ad4fb61e03d9b3040d792d28d1d3dd9583ef15ba
Author: Chenthill Palanisamy <pchenthill novell com>
Date:   Tue Jun 16 22:10:39 2009 +0530

    Check for the presence of message id.

 camel/providers/groupwise/camel-groupwise-folder.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/camel/providers/groupwise/camel-groupwise-folder.c b/camel/providers/groupwise/camel-groupwise-folder.c
index d51c328..dc79116 100644
--- a/camel/providers/groupwise/camel-groupwise-folder.c
+++ b/camel/providers/groupwise/camel-groupwise-folder.c
@@ -2056,7 +2056,8 @@ groupwise_folder_item_to_msg( CamelFolder *folder,
 	if (!has_mime_822 ) {
 		/* Set Message Id */
 		message_id = e_gw_item_get_message_id (item);
-		camel_medium_add_header (CAMEL_MEDIUM (msg), "Message-Id", message_id);
+		if (message_id)
+			camel_medium_add_header (CAMEL_MEDIUM (msg), "Message-Id", message_id);
 
 		/* Set parent threads */
 		parent_threads = e_gw_item_get_parent_thread_ids (item);