Get rid of more tvb_get_nstringz* calls.

Add an FT_STRINGZPAD type, for null-padded strings (typically
fixed-length fields, where the string can be up to the length of the
field, and is null-padded if it's shorter than that), and use it.  Use
IS_FT_STRING() in more cases, so that less code needs to know what types
are string types.

Add a tvb_get_stringzpad() routine, which gets null-padded strings.
Currently, it does the same thing that tvb_get_string_enc() does, but
that might change if we don't store string values as null-terminated
strings.

Change-Id: I46f56e130de8f419a19b56ded914e24cc7518a66
Reviewed-on: https://code.wireshark.org/review/1082
Reviewed-by: Guy Harris <guy@alum.mit.edu>

9 files changed, 72 insertions, 89 deletions

diff --git a/epan/dissectors/packet-fw1.c b/epan/dissectors/packet-fw1.c
index 51ed2942a0..e4ff9e3a7d 100644
--- a/epan/dissectors/packet-fw1.c
+++ b/epan/dissectors/packet-fw1.c
@@ -160,8 +160,7 @@ dissect_fw1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   if (fw1_with_uuid)
     iface_len = 6;
 
-  interface_name=(char *)wmem_alloc(wmem_packet_scope(), iface_len+1);
-  tvb_get_nstringz0(tvb, 2, iface_len+1, interface_name);
+  interface_name=tvb_get_stringzpad(wmem_packet_scope(), tvb, 2, iface_len, ENC_ASCII|ENC_NA);
 
   /* Known interface name - if not, remember it */
   found=FALSE;
diff --git a/epan/dissectors/packet-hartip.c b/epan/dissectors/packet-hartip.c
index c8edad2b94..6d6b0d71d3 100644
--- a/epan/dissectors/packet-hartip.c
+++ b/epan/dissectors/packet-hartip.c
@@ -384,26 +384,7 @@ dissect_float(proto_tree *tree, int hf, tvbuff_t *tvb, gint offset)
 }
 
 static gint
-dissect_string(proto_tree *tree, int hf, const char *name, int len,
-               tvbuff_t *tvb, gint offset)
-{
-  proto_item *ti;
-  char       *str;
-
-  str = (char *)wmem_alloc(wmem_packet_scope(), 256);
-
-  ti = proto_tree_add_item(tree, hf, tvb, offset, len, ENC_NA);
-  if (len < 256) {
-    (void) tvb_get_nstringz0(tvb, offset, len + 1, str);
-    proto_item_set_text(ti, "%s: %s", name, str);
-  }
-
-  return len;
-}
-
-static gint
-dissect_packAscii(proto_tree *tree, int hf, const char *name, int len,
-                  tvbuff_t *tvb, gint offset)
+dissect_packAscii(proto_tree *tree, int hf, tvbuff_t *tvb, gint offset, int len)
 {
   gushort     usIdx;
   gushort     usGroupCnt;
@@ -411,19 +392,16 @@ dissect_packAscii(proto_tree *tree, int hf, const char *name, int len,
   gushort     usMask;
   gint        iIndex;
   gint        i   = 0;
-  proto_item *ti;
   gushort     buf[4];
   guint8     *tmp;
   char       *str = NULL;
 
-  str = (char *)wmem_alloc(wmem_packet_scope(), 256+1);
-
-  ti = proto_tree_add_item(tree, hf, tvb, offset, len, ENC_NA);
-
-  DISSECTOR_ASSERT(len < 3 * (256/4));
   tmp = (guint8 *)wmem_alloc0(wmem_packet_scope(), len);
   tvb_memcpy(tvb, tmp, offset, len);
 
+  /* Maximum possible unpacked length = (len / 3) * 4 */
+  str = (char *)wmem_alloc(wmem_packet_scope(), ((len / 3) * 4)+1);
+
   iIndex = 0;
   usMaxGroups = (gushort)(len / 3);
   for (usGroupCnt = 0; usGroupCnt < usMaxGroups; usGroupCnt++) {
@@ -446,7 +424,8 @@ dissect_packAscii(proto_tree *tree, int hf, const char *name, int len,
     }
   }
   str[i] = '\0';
-  proto_item_set_text(ti, "%s: %s", name, str);
+
+  proto_tree_add_string(tree, hf, tvb, offset, len, str);
 
   return len;
 }
@@ -630,8 +609,8 @@ static gint
 dissect_cmd13(proto_tree *body_tree, tvbuff_t *tvb, gint offset, gint bodylen)
 {
   if (bodylen >= 21) {
-    offset += dissect_packAscii(body_tree, hf_hartip_pt_rsp_tag, "Tag", 6,                       tvb, offset);
-    offset += dissect_packAscii(body_tree, hf_hartip_pt_rsp_packed_descriptor, "descriptor", 12, tvb, offset);
+    offset += dissect_packAscii(body_tree, hf_hartip_pt_rsp_tag, tvb, offset, 6);
+    offset += dissect_packAscii(body_tree, hf_hartip_pt_rsp_packed_descriptor, tvb, offset, 12);
     offset += dissect_byte(body_tree,      hf_hartip_pt_rsp_day,                                 tvb, offset);
     offset += dissect_byte(body_tree,      hf_hartip_pt_rsp_month,                               tvb, offset);
     /*offset += */dissect_byte(body_tree,      hf_hartip_pt_rsp_year,                                tvb, offset);
@@ -688,13 +667,16 @@ dissect_parse_hart_cmds(proto_tree *body_tree, tvbuff_t *tvb, guint8 cmd,
     return dissect_cmd9(body_tree, tvb, offset, bodylen);
   case 12:
     if (bodylen >= 24)
-      return dissect_packAscii(body_tree, hf_hartip_pt_rsp_message, "Message", 24, tvb, offset);
+      return dissect_packAscii(body_tree, hf_hartip_pt_rsp_message, tvb, offset, 24);
     break;
   case 13:
     return dissect_cmd13(body_tree, tvb, offset, bodylen);
   case 20:
-    if (bodylen >= 32)
-      return dissect_string(body_tree, hf_hartip_pt_rsp_tag, "Tag", 32, tvb, offset);
+    if (bodylen >= 32) {
+      proto_tree_add_item(body_tree, hf_hartip_pt_rsp_tag, tvb, offset, 32,
+                          ENC_ASCII|ENC_NA);
+      return 32;
+    }
     break;
   case 48:
     return dissect_cmd48(body_tree, tvb, offset, bodylen);
@@ -1438,7 +1420,7 @@ proto_register_hartip(void)
     /* command 13 */
     { &hf_hartip_pt_rsp_packed_descriptor,
       { "Descriptor",           "hart_ip.pt.rsp.descriptor",
-        FT_BYTES, BASE_NONE, NULL, 0x0,
+        FT_STRINGZPAD, BASE_NONE, NULL, 0x0,
         NULL, HFILL }
     },
     { &hf_hartip_pt_rsp_day,
@@ -1460,14 +1442,14 @@ proto_register_hartip(void)
     /* Tag */
     { &hf_hartip_pt_rsp_tag,
       { "Tag",           "hart_ip.pt.rsp.tag",
-        FT_BYTES, BASE_NONE, NULL, 0x0,
+        FT_STRINGZPAD, BASE_NONE, NULL, 0x0,
         NULL, HFILL }
     },
 
     /* Message */
     { &hf_hartip_pt_rsp_message,
       { "Message",           "hart_ip.pt.rsp.message",
-        FT_BYTES, BASE_NONE, NULL, 0x0,
+        FT_STRINGZPAD, BASE_NONE, NULL, 0x0,
         NULL, HFILL }
     },
 
diff --git a/epan/dissectors/packet-ospf.c b/epan/dissectors/packet-ospf.c
index 281ba265b6..6d1a0a3b20 100644
--- a/epan/dissectors/packet-ospf.c
+++ b/epan/dissectors/packet-ospf.c
@@ -1042,7 +1042,7 @@ dissect_ospf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     guint16 cksum, computed_cksum;
     guint length, reported_length;
     guint16 auth_type;
-    char auth_data[8+1];
+    guint8 *auth_data;
     int crypto_len = 0;
     unsigned int ospf_header_length;
     guint8 instance_ID;
@@ -1210,7 +1210,7 @@ dissect_ospf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
                 break;
 
             case OSPF_AUTH_SIMPLE:
-                tvb_get_nstringz0(tvb, 16, 8+1, auth_data);
+                auth_data = tvb_get_string_enc(wmem_packet_scope(), tvb, 16, 8, ENC_ASCII|ENC_NA);
                 proto_tree_add_text(ospf_header_tree, tvb, 16, 8, "Auth Data: %s", auth_data);
                 break;
 
diff --git a/epan/dissectors/packet-quake3.c b/epan/dissectors/packet-quake3.c
index c9d5fad22d..3b8bfc328f 100644
--- a/epan/dissectors/packet-quake3.c
+++ b/epan/dissectors/packet-quake3.c
@@ -144,7 +144,7 @@ dissect_quake3_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo _U_,
 	proto_tree	*cl_tree = NULL;
 	proto_item	*text_item = NULL;
 	proto_tree	*text_tree = NULL;
-	guint8		text[2048];
+	guint8		*text;
 	int		len;
 	int		offset;
 	guint32		marker;
@@ -165,11 +165,21 @@ dissect_quake3_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo _U_,
 	/* all the rest of the packet is just text */
 	offset = 4;
 
-	len = tvb_get_nstringz0(tvb, offset, sizeof(text), text);
+	/*
+	 * XXX - is there ever more than one null-terminated string in
+	 * the packet?
+	 *
+	 * XXX - is the string guaranteed to be null-terminated (so
+	 * that if there's no NUL at the end, it's an error)?
+	 *
+	 * XXX - are non-ASCII characters supported and, if so, what
+	 * encoding is used for them?
+	 */
+	text = tvb_get_stringz_enc(wmem_packet_scope(), tvb, offset, &len, ENC_ASCII|ENC_NA);
         if (cl_tree) {
 		text_item = proto_tree_add_string(cl_tree,
 				hf_quake3_connectionless_text,
-				tvb, offset, len + 1, text);
+				tvb, offset, len, text);
 		text_tree = proto_item_add_subtree(text_item, ett_quake3_connectionless_text);
 	}
 
@@ -321,7 +331,7 @@ dissect_quake3_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo _U_,
 					val_to_str_const(command, names_command, "Unknown"));
         }
 
-        /*offset += len + 1;*/
+        /*offset += len;*/
 
 }
 
diff --git a/epan/dissectors/packet-quakeworld.c b/epan/dissectors/packet-quakeworld.c
index 16ac74a911..4ceb8a4fad 100644
--- a/epan/dissectors/packet-quakeworld.c
+++ b/epan/dissectors/packet-quakeworld.c
@@ -90,8 +90,8 @@ static	char	com_token[MAX_TEXT_SIZE+1];
 static	int	com_token_start;
 static	int	com_token_length;
 
-static char *
-COM_Parse (char *data)
+static const char *
+COM_Parse (const char *data)
 {
 	int	c;
 	int	len;
@@ -198,7 +198,7 @@ Cmd_Argv_length(int arg)
 
 
 static void
-Cmd_TokenizeString(char* text)
+Cmd_TokenizeString(const char* text)
 {
 	int start;
 
@@ -349,7 +349,7 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 {
 	proto_tree	*cl_tree   = NULL;
 	proto_tree	*text_tree = NULL;
-	guint8		text[MAX_TEXT_SIZE+1];
+	guint8		*text;
 	int		len;
 	int		offset;
 	guint32		marker;
@@ -370,13 +370,13 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 	/* all the rest of the packet is just text */
         offset = 4;
 
-        len = tvb_get_nstringz0(tvb, offset, sizeof(text), text);
+	text = tvb_get_stringz_enc(wmem_packet_scope(), tvb, offset, &len, ENC_ASCII|ENC_NA);
 	/* actually, we should look for a eol char and stop already there */
 
         if (cl_tree) {
 		proto_item *text_item;
                 text_item = proto_tree_add_string(cl_tree, hf_quakeworld_connectionless_text,
-						  tvb, offset, len + 1, text);
+						  tvb, offset, len, text);
 		text_tree = proto_item_add_subtree(text_item, ett_quakeworld_connectionless_text);
         }
 
@@ -469,7 +469,7 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 					tvb, offset, command_len, command);
 				argument_item = proto_tree_add_string(text_tree,
 					hf_quakeworld_connectionless_arguments,
-					tvb, offset + Cmd_Argv_start(1), len + 1 - Cmd_Argv_start(1),
+					tvb, offset + Cmd_Argv_start(1), len - Cmd_Argv_start(1),
 					text + Cmd_Argv_start(1));
 				argument_tree =	proto_item_add_subtree(argument_item,
 								       ett_quakeworld_connectionless_arguments);
@@ -504,7 +504,7 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 			command_len = 1;
 		} else {
 			command = "Unknown";
-			command_len = len;
+			command_len = len - 1;
 		}
 	}
 	else {
@@ -529,7 +529,7 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 			/* string, atoi */
 		} else {
 			command = "Unknown";
-			command_len = len;
+			command_len = len - 1;
 		}
 	}
 
@@ -539,7 +539,7 @@ dissect_quakeworld_ConnectionlessPacket(tvbuff_t *tvb, packet_info *pinfo,
 		proto_tree_add_string(text_tree, hf_quakeworld_connectionless_command,
 			tvb, offset, command_len, command);
 	}
-        /*offset += len + 1;*/
+	/*offset += len;*/
 }
 
 
diff --git a/epan/dissectors/packet-rsync.c b/epan/dissectors/packet-rsync.c
index 95eb7f36c1..9448d70f7e 100644
--- a/epan/dissectors/packet-rsync.c
+++ b/epan/dissectors/packet-rsync.c
@@ -123,17 +123,19 @@ static dissector_handle_t rsync_handle;
 
 static guint glb_rsync_tcp_port = TCP_PORT_RSYNC;
 
+#define VERSION_LEN     4           /* 2 digits for main version; '.'; 1 digit for sub version */
+
 static void
 dissect_rsync_version_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *rsync_tree, enum rsync_who me)
 {
     int   offset = 0;
-    gchar version[5];           /* 2 digits for main version; '.'; 1 digit for sub version; NULL */
+    guint8 *version;
 
     proto_tree_add_item(rsync_tree, &hfi_rsync_hdr_magic, tvb, offset, RSYNCD_MAGIC_HEADER_LEN, ENC_ASCII|ENC_NA);
     offset += RSYNCD_MAGIC_HEADER_LEN;
     offset += 1; /* skip the space */
-    proto_tree_add_item(rsync_tree, &hfi_rsync_hdr_version, tvb, offset, sizeof(version)-1, ENC_ASCII|ENC_NA);
-    tvb_get_nstringz0(tvb, offset, sizeof(version), version);
+    proto_tree_add_item(rsync_tree, &hfi_rsync_hdr_version, tvb, offset, VERSION_LEN, ENC_ASCII|ENC_NA);
+    version = tvb_get_string_enc(wmem_packet_scope(),tvb, offset, VERSION_LEN, ENC_ASCII|ENC_NA);
 
     col_add_fstr(pinfo->cinfo, COL_INFO, "%s Initialisation (Version %s)", (me == SERVER ? "Server" : "Client"), version);
 }
diff --git a/epan/dissectors/packet-smb-browse.c b/epan/dissectors/packet-smb-browse.c
index 3c55bd1250..4c556ed0af 100644
--- a/epan/dissectors/packet-smb-browse.c
+++ b/epan/dissectors/packet-smb-browse.c
@@ -570,6 +570,7 @@ dissect_smb_server_type_flags(tvbuff_t *tvb, int offset, packet_info *pinfo,
 	return offset;
 }
 
+#define HOST_NAME_LEN	16
 
 static void
 dissect_mailslot_browse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
@@ -579,8 +580,7 @@ dissect_mailslot_browse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 	proto_tree *tree = NULL;
 	proto_item *item = NULL;
 	guint32 periodicity;
-	gchar host_name[17];
-	gchar *utf8_host_name;
+	guint8 *host_name;
 	gint namelen;
 	guint8 server_count, reset_cmd;
 	guint8 os_major_ver, os_minor_ver;
@@ -621,22 +621,16 @@ dissect_mailslot_browse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 		offset += 4;
 
 		/* server name */
-		tvb_get_nstringz0(tvb, offset, sizeof(host_name), host_name);
-		utf8_host_name = g_convert(host_name, strlen(host_name),
-			"UTF-8", "CP437", NULL, NULL, NULL);
-		if (utf8_host_name == NULL)
-			utf8_host_name = host_name;
-		col_append_fstr(pinfo->cinfo, COL_INFO, " %s", utf8_host_name);
+		host_name = tvb_get_stringzpad(wmem_packet_scope(), tvb, offset, HOST_NAME_LEN, ENC_CP437|ENC_NA);
+		col_append_fstr(pinfo->cinfo, COL_INFO, " %s", host_name);
 		proto_tree_add_string_format(tree, hf_server_name,
-			tvb, offset, 16,
-			utf8_host_name,
+			tvb, offset, HOST_NAME_LEN,
+			host_name,
 			(cmd==BROWSE_DOMAIN_ANNOUNCEMENT)?
 				"Domain/Workgroup: %s":
 				"Host Name: %s",
-			utf8_host_name);
-		if (utf8_host_name != host_name)
-			g_free(utf8_host_name);
-		offset += 16;
+			host_name);
+		offset += HOST_NAME_LEN;
 
 		/* Windows version (See "OSVERSIONINFO Structure" on MSDN) */
 		os_major_ver = tvb_get_guint8(tvb, offset);
@@ -838,7 +832,6 @@ dissect_mailslot_lanman(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 	/* Put in something, and replace it later */
 	col_add_str(pinfo->cinfo, COL_INFO, val_to_str(cmd, commands, "Unknown command:0x%02x"));
 
-
 	if (parent_tree) {
 		item = proto_tree_add_item(parent_tree, proto_smb_browse, tvb, offset, -1, ENC_NA);
 
@@ -853,7 +846,6 @@ dissect_mailslot_lanman(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 	case BROWSE_DOMAIN_ANNOUNCEMENT:
 	case BROWSE_LOCAL_MASTER_ANNOUNCEMENT:
 	case BROWSE_HOST_ANNOUNCE:
-
 		/* update count */
 		proto_tree_add_item(tree, hf_update_count, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 		offset += 1;
@@ -888,7 +880,7 @@ dissect_mailslot_lanman(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 		offset += 2;
 
 		/* server name */
-		host_name = tvb_get_const_stringz(tvb, offset, &namelen);
+		host_name = tvb_get_stringz_enc(wmem_packet_scope(), tvb, offset, &namelen, ENC_CP437|ENC_NA);
 		col_append_fstr(pinfo->cinfo, COL_INFO, " %s", host_name);
 
 		proto_tree_add_item(tree, hf_server_name,
@@ -900,7 +892,7 @@ dissect_mailslot_lanman(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tr
 		proto_tree_add_item(tree,
 			(cmd==BROWSE_DOMAIN_ANNOUNCEMENT)?
 			    hf_mb_server_name : hf_server_comment,
-			tvb, offset, namelen, ENC_ASCII|ENC_NA);
+			tvb, offset, namelen, ENC_CP437|ENC_NA);
 		break;
 	}
 }
diff --git a/epan/dissectors/packet-tacacs.c b/epan/dissectors/packet-tacacs.c
index 29339e7f6e..2ea2c8105b 100644
--- a/epan/dissectors/packet-tacacs.c
+++ b/epan/dissectors/packet-tacacs.c
@@ -396,14 +396,15 @@ static void
 dissect_tacplus_args_list( tvbuff_t *tvb, proto_tree *tree, int data_off, int len_off, int arg_cnt )
 {
 	int i;
-	guint8	buff[257];
+	int len;
+	guint8 *value;
 	for(i=0;i<arg_cnt;i++){
-		int len=tvb_get_guint8(tvb,len_off+i);
+		len=tvb_get_guint8(tvb,len_off+i);
 		proto_tree_add_uint_format(tree, hf_tacplus_arg_length, tvb, len_off+i, 1, len,
 									"Arg[%d] length: %d", i, len);
-		tvb_get_nstringz0(tvb, data_off, len+1, buff);
-		proto_tree_add_string_format(tree, hf_tacplus_arg_value, tvb, data_off, len, buff,
-									"Arg[%d] value: %s", i, buff);
+		value=tvb_get_string_enc(wmem_packet_scope(), tvb, data_off, len, ENC_ASCII|ENC_NA);
+		proto_tree_add_string_format(tree, hf_tacplus_arg_value, tvb, data_off, len, value,
+									"Arg[%d] value: %s", i, value);
 		data_off+=len;
 	}
 }
diff --git a/epan/dissectors/packet-who.c b/epan/dissectors/packet-who.c
index 05afd84cce..d1c604bb5e 100644
--- a/epan/dissectors/packet-who.c
+++ b/epan/dissectors/packet-who.c
@@ -56,12 +56,9 @@ RWHOD(8)                 UNIX System Manager's Manual                 RWHOD(8)
 (20 each)                  int     we_idle;
                    } wd_we[1024 / sizeof (struct whoent)];
            };
-
- Linux 2.0                       May 13, 1997                                2
-
  *
  */
-
+ 
 void proto_register_who(void);
 void proto_reg_handoff_who(void);
 
@@ -94,7 +91,7 @@ dissect_who(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 	int		offset = 0;
 	proto_tree	*who_tree = NULL;
 	proto_item	*who_ti = NULL;
-	gchar		server_name[33];
+	guint8		*server_name;
 	double		loadav_5 = 0.0, loadav_10 = 0.0, loadav_15 = 0.0;
 	nstime_t	ts;
 
@@ -135,7 +132,7 @@ dissect_who(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 	}
 	offset += 4;
 
-	tvb_get_nstringz0(tvb, offset, sizeof(server_name), (guint8*)server_name);
+	server_name = tvb_get_stringzpad(wmem_packet_scope(), tvb, offset, 32, ENC_ASCII|ENC_NA);
 	if (tree)
 		proto_tree_add_string(who_tree, hf_who_hostname, tvb, offset,
 		    32, server_name);
@@ -184,8 +181,8 @@ dissect_whoent(tvbuff_t *tvb, int offset, proto_tree *tree)
 	proto_tree	*whoent_tree = NULL;
 	proto_item	*whoent_ti = NULL;
 	int		line_offset = offset;
-	gchar		out_line[9];
-	gchar		out_name[9];
+	guint8		*out_line;
+	guint8		*out_name;
 	nstime_t	ts;
 	int		whoent_num = 0;
 	guint32		idle_secs; /* say that out loud... */
@@ -198,12 +195,12 @@ dissect_whoent(tvbuff_t *tvb, int offset, proto_tree *tree)
 		    line_offset, SIZE_OF_WHOENT, ENC_NA);
 		whoent_tree = proto_item_add_subtree(whoent_ti, ett_whoent);
 
-	    	tvb_get_nstringz0(tvb, line_offset, sizeof(out_line), (guint8*)out_line);
+		out_line = tvb_get_stringzpad(wmem_packet_scope(), tvb, line_offset, 8, ENC_ASCII|ENC_NA);
 		proto_tree_add_string(whoent_tree, hf_who_tty, tvb, line_offset,
 		    8, out_line);
 		line_offset += 8;
 
-	    	tvb_get_nstringz0(tvb, line_offset, sizeof(out_name), (guint8*)out_name);
+		out_name = tvb_get_stringzpad(wmem_packet_scope(), tvb, line_offset, 8, ENC_ASCII|ENC_NA);
 		proto_tree_add_string(whoent_tree, hf_who_uid, tvb, line_offset,
 		    8, out_name);
 		line_offset += 8;