Optimize empty strings to NULL pointers.

svn path=/trunk/; revision=29298

1 files changed, 113 insertions, 113 deletions

diff --git a/epan/dissectors/packet-gsm_a_dtap.c b/epan/dissectors/packet-gsm_a_dtap.c
index 68864be749..bbed499afd 100644
--- a/epan/dissectors/packet-gsm_a_dtap.c
+++ b/epan/dissectors/packet-gsm_a_dtap.c
@@ -3804,7 +3804,7 @@ dtap_mm_auth_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_DTAP, DE_AUTH_PARAM_RAND);
 
-	ELEM_OPT_TLV(0x20, GSM_A_PDU_TYPE_DTAP, DE_AUTH_PARAM_AUTN, "");
+	ELEM_OPT_TLV(0x20, GSM_A_PDU_TYPE_DTAP, DE_AUTH_PARAM_AUTN, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -3826,7 +3826,7 @@ dtap_mm_auth_resp(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_DTAP, DE_AUTH_RESP_PARAM);
 
-	ELEM_OPT_TLV(0x21, GSM_A_PDU_TYPE_DTAP, DE_AUTH_RESP_PARAM_EXT, "");
+	ELEM_OPT_TLV(0x21, GSM_A_PDU_TYPE_DTAP, DE_AUTH_RESP_PARAM_EXT, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -3848,7 +3848,7 @@ dtap_mm_auth_fail(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_DTAP, DE_REJ_CAUSE);
 
-	ELEM_OPT_TLV(0x22, GSM_A_PDU_TYPE_DTAP, DE_AUTH_FAIL_PARAM, "");
+	ELEM_OPT_TLV(0x22, GSM_A_PDU_TYPE_DTAP, DE_AUTH_FAIL_PARAM, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -3912,11 +3912,11 @@ dtap_mm_cm_reestab_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint le
 
 	if (curr_len <= 0) return;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, NULL);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
-	ELEM_OPT_TV(0x13, GSM_A_PDU_TYPE_COMMON, DE_LAI, "");
+	ELEM_OPT_TV(0x13, GSM_A_PDU_TYPE_COMMON, DE_LAI, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4067,11 +4067,11 @@ dtap_mm_cm_srvc_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	if (curr_len <= 0) return;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, NULL);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
-	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, "");
+	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4149,7 +4149,7 @@ dtap_mm_id_resp(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4171,7 +4171,7 @@ dtap_mm_imsi_det_ind(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_1);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4193,18 +4193,18 @@ dtap_mm_loc_upd_acc(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_COMMON, DE_LAI);
 
-	ELEM_OPT_TLV(0x17, GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_OPT_TLV(0x17, GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
-	ELEM_OPT_T(0xa1, GSM_A_PDU_TYPE_DTAP, DE_FOP, "");
+	ELEM_OPT_T(0xa1, GSM_A_PDU_TYPE_DTAP, DE_FOP, NULL);
 
 	/* CTS permission O T 1 10.5.3.10 */
-	ELEM_OPT_T(0xa2, GSM_A_PDU_TYPE_DTAP, DE_CTS_PERM, "");
+	ELEM_OPT_T(0xa2, GSM_A_PDU_TYPE_DTAP, DE_CTS_PERM, NULL);
 
 	/* PLMN list O TLV 5-47 10.5.1.13 */
 	ELEM_OPT_TLV(0x4a, GSM_A_PDU_TYPE_COMMON, DE_PLMN_LIST, " Equivalent");
 
 	/* 34 Emergency Number List O TLV 5-50 10.5.3.13 */
-	ELEM_OPT_TLV(0x34, GSM_A_PDU_TYPE_DTAP, DE_EMERGENCY_NUM_LIST, "");
+	ELEM_OPT_TLV(0x34, GSM_A_PDU_TYPE_DTAP, DE_EMERGENCY_NUM_LIST, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4326,9 +4326,9 @@ dtap_mm_loc_upd_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_COMMON, DE_MS_CM_1);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
-	ELEM_OPT_TLV(0x33, GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, "");
+	ELEM_OPT_TLV(0x33, GSM_A_PDU_TYPE_COMMON, DE_MS_CM_2, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4357,9 +4357,9 @@ dtap_mm_mm_info(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TV(0x47, GSM_A_PDU_TYPE_DTAP, DE_TIME_ZONE_TIME, " - Universal Time and Local Time Zone");
 
-	ELEM_OPT_TLV(0x48, GSM_A_PDU_TYPE_DTAP, DE_LSA_ID, "");
+	ELEM_OPT_TLV(0x48, GSM_A_PDU_TYPE_DTAP, DE_LSA_ID, NULL);
 
-	ELEM_OPT_TLV(0x49, GSM_A_PDU_TYPE_DTAP, DE_DAY_SAVING_TIME, "");
+	ELEM_OPT_TLV(0x49, GSM_A_PDU_TYPE_DTAP, DE_DAY_SAVING_TIME, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4401,7 +4401,7 @@ dtap_mm_tmsi_realloc_cmd(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_COMMON, DE_LAI);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_COMMON, DE_MID, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4430,15 +4430,15 @@ dtap_cc_alerting(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4464,13 +4464,13 @@ dtap_cc_call_conf(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, " 2");
 
-	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
-	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, "");
+	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, NULL);
 
-	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, "");
+	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, NULL);
 
-	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, "");
+	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4496,13 +4496,13 @@ dtap_cc_call_proceed(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, " 2");
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, "");
+	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, NULL);
 
-	ELEM_OPT_TLV(0x2f, GSM_A_PDU_TYPE_DTAP, DE_NET_CC_CAP, "");
+	ELEM_OPT_TLV(0x2f, GSM_A_PDU_TYPE_DTAP, DE_NET_CC_CAP, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4561,7 +4561,7 @@ dtap_cc_congestion_control(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guin
 
 	if (curr_len <= 0) return;
 
-	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4581,21 +4581,21 @@ dtap_cc_connect(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TLV(0x4c, GSM_A_PDU_TYPE_DTAP, DE_CONN_NUM, "");
+	ELEM_OPT_TLV(0x4c, GSM_A_PDU_TYPE_DTAP, DE_CONN_NUM, NULL);
 
-	ELEM_OPT_TLV(0x4d, GSM_A_PDU_TYPE_DTAP, DE_CONN_SUB_ADDR, "");
+	ELEM_OPT_TLV(0x4d, GSM_A_PDU_TYPE_DTAP, DE_CONN_SUB_ADDR, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
-	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, "");
+	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4615,19 +4615,19 @@ dtap_cc_disconnect(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
-	ELEM_OPT_TLV(0x7b, GSM_A_PDU_TYPE_DTAP, DE_ALLOWED_ACTIONS, "");
+	ELEM_OPT_TLV(0x7b, GSM_A_PDU_TYPE_DTAP, DE_ALLOWED_ACTIONS, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4647,11 +4647,11 @@ dtap_cc_emerg_setup(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, "");
+	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, NULL);
 
-	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, "");
+	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, NULL);
 
-	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, "");
+	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, NULL);
 
 	ELEM_OPT_TLV(0x2e, GSM_A_PDU_TYPE_DTAP, DE_SERV_CAT, " Emergency");
 
@@ -4673,11 +4673,11 @@ dtap_cc_facility(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4703,7 +4703,7 @@ dtap_cc_hold_rej(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4723,15 +4723,15 @@ dtap_cc_modify(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, NULL);
 
-	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, "");
+	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, NULL);
 
-	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, "");
+	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, NULL);
 
-	ELEM_OPT_T(0xa3, GSM_A_PDU_TYPE_DTAP, DE_REV_CALL_SETUP_DIR, "");
+	ELEM_OPT_T(0xa3, GSM_A_PDU_TYPE_DTAP, DE_REV_CALL_SETUP_DIR, NULL);
 
-	ELEM_OPT_T(0xa4, GSM_A_PDU_TYPE_DTAP, DE_IMM_MOD_IND, "");
+	ELEM_OPT_T(0xa4, GSM_A_PDU_TYPE_DTAP, DE_IMM_MOD_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4751,13 +4751,13 @@ dtap_cc_modify_complete(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint l
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, NULL);
 
-	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, "");
+	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, NULL);
 
-	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, "");
+	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, NULL);
 
-	ELEM_OPT_T(0xa3, GSM_A_PDU_TYPE_DTAP, DE_REV_CALL_SETUP_DIR, "");
+	ELEM_OPT_T(0xa3, GSM_A_PDU_TYPE_DTAP, DE_REV_CALL_SETUP_DIR, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4777,13 +4777,13 @@ dtap_cc_modify_rej(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, NULL);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
-	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, "");
+	ELEM_OPT_TLV(0x7c, GSM_A_PDU_TYPE_DTAP, DE_LLC, NULL);
 
-	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, "");
+	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4823,9 +4823,9 @@ dtap_cc_progress(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4845,7 +4845,7 @@ dtap_cc_cc_est(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_SETUP_CONTAINER, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_SETUP_CONTAINER, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4871,9 +4871,9 @@ dtap_cc_cc_est_conf(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, " 2");
 
-	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
-	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, "");
+	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4893,17 +4893,17 @@ dtap_cc_release(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, " 2");
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4925,7 +4925,7 @@ dtap_cc_recall(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_DTAP, DE_RECALL_TYPE);
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4945,15 +4945,15 @@ dtap_cc_release_complete(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_OPT_TLV(0x08, GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -4973,7 +4973,7 @@ dtap_cc_retrieve_rej(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5008,23 +5008,23 @@ dtap_cc_setup(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TLV(0x04, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, " 2");
 
-	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_OPT_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, "");
+	ELEM_OPT_TLV(0x1e, GSM_A_PDU_TYPE_DTAP, DE_PROG_IND, NULL);
 
-	ELEM_OPT_TV(0x34, GSM_A_PDU_TYPE_DTAP, DE_SIGNAL, "");
+	ELEM_OPT_TV(0x34, GSM_A_PDU_TYPE_DTAP, DE_SIGNAL, NULL);
 
-	ELEM_OPT_TLV(0x5c, GSM_A_PDU_TYPE_DTAP, DE_CLG_PARTY_BCD_NUM, "");
+	ELEM_OPT_TLV(0x5c, GSM_A_PDU_TYPE_DTAP, DE_CLG_PARTY_BCD_NUM, NULL);
 
-	ELEM_OPT_TLV(0x5d, GSM_A_PDU_TYPE_DTAP, DE_CLG_PARTY_SUB_ADDR, "");
+	ELEM_OPT_TLV(0x5d, GSM_A_PDU_TYPE_DTAP, DE_CLG_PARTY_SUB_ADDR, NULL);
 
-	ELEM_OPT_TLV(0x5e, GSM_A_PDU_TYPE_DTAP, DE_CLD_PARTY_BCD_NUM, "");
+	ELEM_OPT_TLV(0x5e, GSM_A_PDU_TYPE_DTAP, DE_CLD_PARTY_BCD_NUM, NULL);
 
-	ELEM_OPT_TLV(0x6d, GSM_A_PDU_TYPE_DTAP, DE_CLD_PARTY_SUB_ADDR, "");
+	ELEM_OPT_TLV(0x6d, GSM_A_PDU_TYPE_DTAP, DE_CLD_PARTY_SUB_ADDR, NULL);
 
-	ELEM_OPT_TLV(0x74, GSM_A_PDU_TYPE_DTAP, DE_RED_PARTY_BCD_NUM, "");
+	ELEM_OPT_TLV(0x74, GSM_A_PDU_TYPE_DTAP, DE_RED_PARTY_BCD_NUM, NULL);
 
-	ELEM_OPT_TLV(0x75, GSM_A_PDU_TYPE_DTAP, DE_RED_PARTY_SUB_ADDR, "");
+	ELEM_OPT_TLV(0x75, GSM_A_PDU_TYPE_DTAP, DE_RED_PARTY_SUB_ADDR, NULL);
 
 	ELEM_OPT_TV_SHORT(0xd0, GSM_A_PDU_TYPE_DTAP, DE_REPEAT_IND, " LLC repeat indicator");
 
@@ -5038,41 +5038,41 @@ dtap_cc_setup(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	ELEM_OPT_TLV(0x7d, GSM_A_PDU_TYPE_DTAP, DE_HLC, " 2");
 
-	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_OPT_TLV(0x7e, GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
 	/* downlink only */
 
-	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, "");
+	ELEM_OPT_TV_SHORT(0x80, GSM_A_PDU_TYPE_COMMON, DE_PRIO, NULL);
 
-	ELEM_OPT_TLV(0x19, GSM_A_PDU_TYPE_DTAP, DE_ALERT_PATTERN, "");
+	ELEM_OPT_TLV(0x19, GSM_A_PDU_TYPE_DTAP, DE_ALERT_PATTERN, NULL);
 
-	ELEM_OPT_TLV(0x2f, GSM_A_PDU_TYPE_DTAP, DE_NET_CC_CAP, "");
+	ELEM_OPT_TLV(0x2f, GSM_A_PDU_TYPE_DTAP, DE_NET_CC_CAP, NULL);
 
-	ELEM_OPT_TLV(0x3a, GSM_A_PDU_TYPE_DTAP, DE_CAUSE_NO_CLI, "");
+	ELEM_OPT_TLV(0x3a, GSM_A_PDU_TYPE_DTAP, DE_CAUSE_NO_CLI, NULL);
 
 	/* Backup bearer capability O TLV 3-15 10.5.4.4a */
-	ELEM_OPT_TLV(0x41, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, "");
+	ELEM_OPT_TLV(0x41, GSM_A_PDU_TYPE_DTAP, DE_BEARER_CAP, NULL);
 
 	/* uplink only */
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
-	ELEM_OPT_T(0xa1, GSM_A_PDU_TYPE_DTAP, DE_CLIR_SUP, "");
+	ELEM_OPT_T(0xa1, GSM_A_PDU_TYPE_DTAP, DE_CLIR_SUP, NULL);
 
-	ELEM_OPT_T(0xa2, GSM_A_PDU_TYPE_DTAP, DE_CLIR_INV, "");
+	ELEM_OPT_T(0xa2, GSM_A_PDU_TYPE_DTAP, DE_CLIR_INV, NULL);
 
-	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, "");
+	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, NULL);
 
 	ELEM_OPT_TLV(0x1d, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, " $(CCBS)$ (advanced recall alignment)");
 
 	ELEM_OPT_TLV(0x1b, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, " (recall alignment Not essential) $(CCBS)$");
 
-	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, "");
+	ELEM_OPT_TLV(0x2d, GSM_A_PDU_TYPE_DTAP, DE_SI, NULL);
 
-	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, "");
+	ELEM_OPT_TLV(0x40, GSM_A_PDU_TYPE_DTAP, DE_SUP_CODEC_LIST, NULL);
 
 	/*A3 Redial O T 1 10.5.4.34 */
-	ELEM_OPT_T(0xA3, GSM_A_PDU_TYPE_DTAP, DE_REDIAL, "");
+	ELEM_OPT_T(0xA3, GSM_A_PDU_TYPE_DTAP, DE_REDIAL, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5092,7 +5092,7 @@ dtap_cc_start_cc(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, "");
+	ELEM_OPT_TLV(0x15, GSM_A_PDU_TYPE_DTAP, DE_CC_CAP, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5112,7 +5112,7 @@ dtap_cc_start_dtmf(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_TV(0x2c, GSM_A_PDU_TYPE_DTAP, DE_KEYPAD_FACILITY, "");
+	ELEM_MAND_TV(0x2c, GSM_A_PDU_TYPE_DTAP, DE_KEYPAD_FACILITY, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5132,7 +5132,7 @@ dtap_cc_start_dtmf_ack(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint le
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_TV(0x2c, GSM_A_PDU_TYPE_DTAP, DE_KEYPAD_FACILITY, "");
+	ELEM_MAND_TV(0x2c, GSM_A_PDU_TYPE_DTAP, DE_KEYPAD_FACILITY, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5152,7 +5152,7 @@ dtap_cc_start_dtmf_rej(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint le
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5172,11 +5172,11 @@ dtap_cc_status(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_FALSE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CAUSE, NULL);
 
 	ELEM_MAND_V(GSM_A_PDU_TYPE_DTAP, DE_CALL_STATE);
 
-	ELEM_OPT_TLV(0x24, GSM_A_PDU_TYPE_DTAP, DE_AUX_STATES, "");
+	ELEM_OPT_TLV(0x24, GSM_A_PDU_TYPE_DTAP, DE_AUX_STATES, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5207,9 +5207,9 @@ dtap_cc_user_info(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_USER_USER, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_USER_USER, NULL);
 
-	ELEM_OPT_T(0xa0, GSM_A_PDU_TYPE_DTAP, DE_MORE_DATA, "");
+	ELEM_OPT_T(0xa0, GSM_A_PDU_TYPE_DTAP, DE_MORE_DATA, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5230,9 +5230,9 @@ dtap_ss_register(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, "");
+	ELEM_MAND_TLV(0x1c, GSM_A_PDU_TYPE_DTAP, DE_FACILITY, NULL);
 
-	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, "");
+	ELEM_OPT_TLV(0x7f, GSM_A_PDU_TYPE_DTAP, DE_SS_VER_IND, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }
@@ -5253,7 +5253,7 @@ dtap_sms_cp_data(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint len)
 
 	is_uplink = IS_UPLINK_TRUE;
 
-	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CP_USER_DATA, "");
+	ELEM_MAND_LV(GSM_A_PDU_TYPE_DTAP, DE_CP_USER_DATA, NULL);
 
 	EXTRANEOUS_DATA_CHECK(curr_len, 0);
 }