ofproto-dpif: Make ofport_dpif_cast() internally consistent.

This function's assertion would dereference a null pointer given a null
'ofport' argument, but its return statement checked for a null pointer
argument.  This commit fixes the inconsistency in favor of supporting
null pointer arguments.  (I discovered this problem while writing a piece
of code that wanted support for a null pointer argument, otherwise I would
resolve the inconsistency in the other direction.)

Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 49bf1e4..0d17dbf 100644 (file)
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -590,7 +590,6 @@ static uint16_t odp_port_to_ofp_port(const struct ofproto_dpif *,
 static struct ofport_dpif *
 ofport_dpif_cast(const struct ofport *ofport)
 {
-    ovs_assert(ofport->ofproto->ofproto_class == &ofproto_dpif_class);
     return ofport ? CONTAINER_OF(ofport, struct ofport_dpif, up) : NULL;
 }