[gupnp] Ensure NOTIFY message has a proper SID

[Jens Georg <jensgeorg src gnome org>]

commit be0665b44a3d0b1433bb48cf959e218c3c6cf965
Author: Jussi Kukkonen <jussi kukkonen intel com>
Date:   Thu Mar 21 15:31:55 2013 +0200

    Ensure NOTIFY message has a proper SID
    
    SID must start with "uuid:" and has to have some value (the uuid
    format was only specified in version 1.1 so that cannot be enforced).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696289

 libgupnp/gupnp-service-proxy.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/libgupnp/gupnp-service-proxy.c b/libgupnp/gupnp-service-proxy.c
index 691ec7e..0b17d1b 100644
--- a/libgupnp/gupnp-service-proxy.c
+++ b/libgupnp/gupnp-service-proxy.c
@@ -1860,7 +1860,9 @@ server_handler (SoupServer        *soup_server,
         seq = atoi (hdr);
 
         hdr = soup_message_headers_get_one (msg->request_headers, "SID");
-        if (hdr == NULL) {
+        if (hdr == NULL ||
+            strlen (hdr) <= strlen ("uuid:") ||
+            strncmp (hdr, "uuid:", strlen ("uuid:")) != 0) {
                 /* No SID */
                 soup_message_set_status (msg, SOUP_STATUS_PRECONDITION_FAILED);