diff --git a/epan/proto.c b/epan/proto.c

index 004acb0..bf98a27 100644

--- a/epan/proto.c

+++ b/epan/proto.c

@@ -1758,6 +1758,31 @@ proto_tree_new_item(field_info *new_fi, proto_tree *tree,

 	return pi;

 }

+

+/*

+ * Validates that field length bytes are available starting from

+ * start (pos/neg). Throws an exception if they aren't.

+ */

+static void

+test_length(header_field_info *hfinfo, tvbuff_t *tvb,

+	    gint start, gint length)

+{

+	gint size = length;

+

+	if (!tvb)

+		return;

+

+	if (hfinfo->type == FT_STRINGZ) {

+		/* If we're fetching until the end of the TVB, only validate

+		 * that the offset is within range.

+		 */

+		if (length == -1)

+			size = 0;

+	}

+

+	tvb_ensure_bytes_exist(tvb, start, size);

+}

+

 /* Gets data from tvbuff, adds it to proto_tree, increments offset,

    and returns proto_item* */

 proto_item *

@@ -1786,6 +1811,8 @@ ptvcursor_add(ptvcursor_t *ptvc, int hfindex, gint length,

 		ptvc->offset += n;

 	}

+	test_length(hfinfo, ptvc->tvb, offset, item_length);

+

 	/* Coast clear. Try and fake it */

 	TRY_TO_FAKE_THIS_ITEM(ptvc->tree, hfindex, hfinfo);

@@ -1795,45 +1822,6 @@ ptvcursor_add(ptvcursor_t *ptvc, int hfindex, gint length,

 		offset, length, encoding);

 }

-/*

- * Validates that field length bytes are available starting from

- * start (pos/neg). Throws an exception if they aren't.

- */

-static void

-test_length(header_field_info *hfinfo, proto_tree *tree, tvbuff_t *tvb,

-	    gint start, gint length, const guint encoding)

-{

-	gint size = length;

-

-	if (!tvb)

-		return;

-

-	if (hfinfo->type == FT_UINT_BYTES || hfinfo->type == FT_UINT_STRING) {

-		guint32 n;

-

-		n = get_uint_value(tree, tvb, start, length, encoding);

-		if (n > size + n) {

-			/* If n > size + n then we have an integer overflow, so

-			 * set size to -1, which will force the

-			 * tvb_ensure_bytes_exist call below to throw a

-			 * ReportedBoundsError

-			 */

-			size = -1;

-		}

-		else {

-			size += n;

-		}

-	} else if (hfinfo->type == FT_STRINGZ) {

-		/* If we're fetching until the end of the TVB, only validate

-		 * that the offset is within range.

-		 */

-		if (length == -1)

-			size = 0;

-	}

-

-	tvb_ensure_bytes_exist(tvb, start, size);

-}

-

 /* Add an item to a proto_tree, using the text label registered to that item;

    the item is extracted from the tvbuff handed to it. */

 proto_item *

@@ -1845,7 +1833,7 @@ proto_tree_add_item(proto_tree *tree, const int hfindex, tvbuff_t *tvb,

 	gint		  item_length;

 	hfinfo = get_hfi_and_length(hfindex, tvb, start, &length, &item_length);

-	test_length(hfinfo, tree, tvb, start, item_length, encoding);

+	test_length(hfinfo, tvb, start, item_length);

 	TRY_TO_FAKE_THIS_ITEM(tree, hfindex, hfinfo);

@@ -7540,7 +7528,7 @@ proto_tree_add_bits_item(proto_tree *tree, const int hf_index, tvbuff_t *tvb,

 	octet_length = (no_of_bits + 7) >> 3;

 	octet_offset = bit_offset >> 3;

-	test_length(hfinfo, tree, tvb, octet_offset, octet_length, encoding);

+	test_length(hfinfo, tvb, octet_offset, octet_length);

 	/* Yes, we try to fake this item again in proto_tree_add_bits_ret_val()

 	 * but only after doing a bunch more work (which we can, in the common