DIO init TX filter update

Added DAO target validation back. There is a case when path control is ff
That is possible when Target have GP address but Node not have yet.

CHANGELOG.md

@@ -9,7 +9,7 @@
 * 
 
 ### Bugfix
-* 
+* Delay sending first DIO until Parent selection and DAO target is published.
 
 
 ## Release v12.6.2 (09-11-2020)

source/RPL/rpl_upward.c

@@ -1840,7 +1840,13 @@ void rpl_upward_dio_timer(rpl_instance_t *instance, uint16_t ticks)
     /* Delay sending first DIO if we are still potentially gathering info */
     /* Important to always send DIOs if we ever have sent any, so we can indicate problems to others */
     if (!rpl_instance_am_root(instance) && !instance->last_advertised_dodag_version && rpl_policy_parent_confirmation_requested()) {
-        // We dont have any valid parent selected
+
+        // We don't have DAO target generated
+        if (ns_list_count(&instance->dao_targets) == 0) {
+            return;
+        }
+
+        // We don't have any valid parent selected
         if (!rpl_instance_parent_selection_ready(instance)) {
             return;
         }