Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 22586: /trunk/epan/dissectors/ /trun

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Wed, 22 Aug 2007 15:34:04 -0700

On Aug 22, 2007, at 3:19 PM, Stig Bjørlykke wrote:

My personal opinion is that this bitfields should be hidden in a
subtree, like this patch:

- proto_tree_add_uint(ip_tree, hf_ip_frag_offset, tvb, offset + 6, 2,
-      (iph->ip_off & IP_OFFSET)*8);
+    tf = proto_tree_add_uint_format(ip_tree, hf_ip_frag_offset, tvb,
offset + 6, 2,
+ iph->ip_off, "Fragment offset: %d", (iph->ip_off & IP_OFFSET)*8);
+    field_tree = proto_item_add_subtree(tf, ett_ip_frag_offset);
+    proto_tree_add_item(field_tree, hf_ip_frag_offset, tvb, offset +
6, 2, FALSE);

That's adding one more layer, with what amounts to a copy of the value underneath it. Other than providing the raw offset, what advantages does it offer? (There, I think, are other dissectors that have bitfields that aren't in a subtree; if the word containing all the bitfields isn't specified as an item of its own in the protocol, I'm not sure it needs to be put into the protocol tree.)