If we don't have any of the packet padding in the tvbuff, don't even try

to add the trailer - that avoids the problem with throwing an exception
inside a CATCH* clause for that same exception.  (XXX - is this a
problem with our exception mechanism? What happens in languages with
built-in exceptions if a

	try
		XXX
	catch YYY
		ZZZ
	end

construct throws exception YYY inside code block ZZZ?  If it doesn't
re-enter ZZZ, that argues that our exception mechanism is buggy or, at
least, violates the Principle of Least Surprise.)

Move the code to put the trailer information into the protocol tree out
of the CATCH2 clause, so the trailer shows up if we *do* have the
trailer information.

svn path=/trunk/; revision=9898

1 files changed, 12 insertions, 9 deletions

diff --git a/packet-ethertype.c b/packet-ethertype.c
index bb63134ff7..487864c310 100644
--- a/packet-ethertype.c
+++ b/packet-ethertype.c
@@ -1,7 +1,7 @@
 /* ethertype.c
  * Routines for calling the right protocol for the ethertype.
  *
- * $Id: packet-ethertype.c,v 1.42 2004/01/28 03:36:37 gerald Exp $
+ * $Id: packet-ethertype.c,v 1.43 2004/01/28 20:09:44 guy Exp $
  *
  * Gilbert Ramirez <gram@alumni.rice.edu>
  *
@@ -263,22 +263,25 @@ add_dix_trailer(proto_tree *fh_tree, int trailer_id, tvbuff_t *tvb,
 	   a trailer. */
 	if (length < length_before) {
 		/*
-		 * Create a tvbuff for the padding.
+		 * Is any of the padding present in the tvbuff?
 		 */
-		TRY {
+		if (tvb_offset_exists(tvb, offset_after_etype + length)) {
+			/*
+			 * Yes - create a tvbuff for the padding.
+			 */
 			trailer_tvb = tvb_new_subset(tvb,
 			    offset_after_etype + length, -1, -1);
-		}
-		CATCH2(BoundsError, ReportedBoundsError) {
-			/* The packet doesn't have "length" bytes worth of
-			   captured data left in it.  No trailer to display. */
+		} else {
+			/*
+			 * No - don't bother showing the trailer.
+			 * XXX - show a Short Frame indication?
+			 */
 			trailer_tvb = NULL;
-			add_ethernet_trailer(fh_tree, trailer_id, tvb, trailer_tvb, fcs_len);
 		}
-		ENDTRY;
 	} else
 		trailer_tvb = NULL;	/* no trailer */
 
+	add_ethernet_trailer(fh_tree, trailer_id, tvb, trailer_tvb, fcs_len);
 }
 
 void