[evolution-data-server] Workaround possible crash in imap_body_decode()

[Milan Crha <mcrha src gnome org>]

commit 7bb77327298819f7845602bfa643281a0cba4e21
Author: Milan Crha <mcrha redhat com>
Date:   Mon Oct 10 10:56:33 2011 +0200

    Workaround possible crash in imap_body_decode()

 camel/providers/imap/camel-imap-utils.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/camel/providers/imap/camel-imap-utils.c b/camel/providers/imap/camel-imap-utils.c
index de74c6c..51b5d04 100644
--- a/camel/providers/imap/camel-imap-utils.c
+++ b/camel/providers/imap/camel-imap-utils.c
@@ -977,7 +977,8 @@ imap_body_decode (const gchar **in,
 		}
 
 		camel_strdown (type);
-		camel_strdown (subtype);
+		if (subtype)
+			camel_strdown (subtype);
 		ctype = camel_content_type_new (type, subtype);
 		g_free (subtype);
 		g_free (type);