[libdmapsharing] Avoid OOB read with buggy servers

[W. Michael Petullo <wmpetullo src gnome org>]

commit 3e347fd3e8e7e20afc562268f27fd3c2b79f4d0e
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Oct 29 11:37:15 2013 +0100

    Avoid OOB read with buggy servers
    
    If the server doesn't start the Content-Range field with "bytes="
    we would have an out-of-bounds read trying to parse the content
    of that field. Fall back to a 0 offset when a parsing error occurs.
    
    See https://bugzilla.redhat.com/show_bug.cgi?id=1024020
    
    https://bugzilla.gnome.org/show_bug.cgi?id=711063

 libdmapsharing/daap-share.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/libdmapsharing/daap-share.c b/libdmapsharing/daap-share.c
index 66cdfe6..e182055 100644
--- a/libdmapsharing/daap-share.c
+++ b/libdmapsharing/daap-share.c
@@ -922,8 +922,13 @@ databases_items_xxx (DMAPShare * share,
                const gchar *s;
                gchar *content_range;
 
-               s = range_header + strlen ("bytes=");   /* bytes= */
-               offset = atoll (s);
+               if (!g_ascii_strncasecmp (range_header, "bytes=", strlen("bytes="))) {
+                       /* Not starting with "bytes=" ? */
+                       offset = 0;
+               } else {
+                       s = range_header + strlen ("bytes=");   /* bytes= */
+                       offset = atoll (s);
+               }
 
                content_range =
                        g_strdup_printf ("bytes %" G_GUINT64_FORMAT "-%"