bugfix: do not trigger e1 bearer setup when no PDU session

It can happen that no PDU session can be setup (e.g., PDU session
already setup). Check that there is at least one before triggering the
message.

Also initialize bearer_req.gNB_cu_cp_ue_id early to avoid uninitialized
IDs (e.g., when no PDU session to be setup).

openair2/RRC/NR/rrc_gNB_NGAP.c

@@ -354,7 +354,9 @@ bool trigger_bearer_setup(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, pdusession
     return false;
   }
   AssertFatal(UE->as_security_active, "logic bug: security should be active when activating DRBs\n");
-  e1ap_bearer_setup_req_t bearer_req = {0};
+  e1ap_bearer_setup_req_t bearer_req = {
+    .gNB_cu_cp_ue_id = UE->rrc_ue_id,
+  };
 
   // Reject bearers setup if there's no CU-UP associated
   if (!is_cuup_associated(rrc)) {
@@ -412,6 +414,10 @@ bool trigger_bearer_setup(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, pdusession
       pdu->DRBnGRanList[0] = fill_e1_drb_to_setup(rrc_drb, session, rrc->configuration.um_on_default_drb, UE->redcap_cap);
     }
   }
+  if (bearer_req.numPDUSessions == 0) {
+    LOG_W(NR_RRC, "UE %d: No PDU sessions to setup, skipping bearer context setup\n", UE->rrc_ue_id);
+    return false;
+  }
   /* Limitation: we assume one fixed CU-UP per UE. We base the selection on
    * NSSAI, but the UE might have multiple PDU sessions with differing slices,
    * in which we might need to select different CU-UPs. In this case, we would