This patch fixes a bug in the test controller.

This patch was developed upstream in OVS 2.4.

diff --git a/lib/learning-switch.c b/lib/learning-switch.c

index ca57911..e037310 100644

--- a/lib/learning-switch.c

+++ b/lib/learning-switch.c

@@ -173,10 +173,49 @@ static void

 lswitch_handshake(struct lswitch *sw)

 {

     enum ofputil_protocol protocol;

-

+    enum ofp_version version;

     send_features_request(sw);

+    version = rconn_get_version(sw->rconn);

+    protocol = ofputil_protocol_from_ofp_version(version);

+    if (version >= OFP13_VERSION) {

+        /* OpenFlow 1.3 and later by default drop packets that miss in the flow

+         * table.  Set up a flow to send packets to the controller by

+         * default. */

+        struct ofputil_flow_mod fm;

+        struct ofpact_output output;

+        struct ofpbuf *msg;

+        int error;

-    protocol = ofputil_protocol_from_ofp_version(rconn_get_version(sw->rconn));

+        ofpact_init_OUTPUT(&output);

+        output.port = OFPP_CONTROLLER;

+        output.max_len = OFP_DEFAULT_MISS_SEND_LEN;

+

+        match_init_catchall(&fm.match);

+        fm.priority = 0;

+        fm.cookie = 0;

+        fm.cookie_mask = 0;

+        fm.new_cookie = 0;

+        fm.modify_cookie = false;

+        fm.table_id = 0;

+        fm.command = OFPFC_ADD;

+        fm.idle_timeout = 0;

+        fm.hard_timeout = 0;

+        fm.importance = 0;

+        fm.buffer_id = UINT32_MAX;

+        fm.out_port = OFPP_NONE;

+        fm.out_group = OFPG_ANY;

+        fm.flags = 0;

+        fm.ofpacts = &output.ofpact;

+        fm.ofpacts_len = sizeof output;

+        fm.delete_reason = 0;

+

+        msg = ofputil_encode_flow_mod(&fm, protocol);

+        error = rconn_send(sw->rconn, msg, NULL);

+        if (error) {

+            VLOG_INFO_RL(&rl, "%s: failed to add default flow (%s)",

+                         rconn_get_name(sw->rconn), ovs_strerror(error));

+        }

+    }

     if (sw->default_flows) {

         struct ofpbuf *msg = NULL;

         int error = 0;

diff --git a/lib/ofp-util.h b/lib/ofp-util.h

index ce6045b..622b928 100644

--- a/lib/ofp-util.h

+++ b/lib/ofp-util.h

@@ -305,8 +305,10 @@ struct ofputil_flow_mod {

     ofp_port_t out_port;

     uint32_t out_group;

     enum ofputil_flow_mod_flags flags;

+    uint16_t importance;     /* Eviction precedence. */

     struct ofpact *ofpacts;  /* Series of "struct ofpact"s. */

     size_t ofpacts_len;      /* Length of ofpacts, in bytes. */

+    enum ofp_flow_removed_reason delete_reason;

 };

 enum ofperr ofputil_decode_flow_mod(struct ofputil_flow_mod *,