Changed packet-tr.c to insert tr.sr, a FT_BOOLEAN field, only if tr.sr

is true. The test for truth now becomes a test for existence. The dfilter
grammar no longer recognizes 'true' and 'false', since you can now check
a boolean field via:

	tr.sr

or by its negation:

	!tr.sr

svn path=/trunk/; revision=591

5 files changed, 19 insertions, 68 deletions

diff --git a/dfilter-grammar.y b/dfilter-grammar.y
index d692267fcc..c7a631b534 100644
--- a/dfilter-grammar.y
+++ b/dfilter-grammar.y
@@ -3,7 +3,7 @@
 /* dfilter-grammar.y
  * Parser for display filters
  *
- * $Id: dfilter-grammar.y,v 1.15 1999/08/26 06:20:48 gram Exp $
+ * $Id: dfilter-grammar.y,v 1.16 1999/08/27 19:27:09 gram Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -87,8 +87,6 @@ static GNode* dfilter_mknode_ipv4_variable(gint id);
 static GNode* dfilter_mknode_existence(gint id);
 static GNode* dfilter_mknode_bytes_value(GByteArray *barray);
 static GNode* dfilter_mknode_bytes_variable(gint id, gint offset, guint length);
-static GNode* dfilter_mknode_boolean_value(gint truth_value);
-static GNode* dfilter_mknode_boolean_variable(gint id);
 
 static guint32 string_to_value(char *s);
 static int ether_str_to_guint8_array(const char *s, guint8 *mac);
@@ -125,7 +123,6 @@ GSList *gnode_slist = NULL;
 %type <node>	ipv4_value ipv4_variable
 %type <node>	variable_name
 %type <node>	bytes_value bytes_variable
-%type <node>	boolean_value boolean_variable
 
 %type <operand>	numeric_relation
 %type <operand>	equality_relation
@@ -222,15 +219,6 @@ relation:	numeric_variable numeric_relation numeric_value
 			$$ = dfilter_mknode_join($1, relation, $2, $3);
 		}
 
-	|	boolean_variable equality_relation boolean_value
-		{
-			$$ = dfilter_mknode_join($1, relation, $2, $3);
-		}
-	|	boolean_variable equality_relation boolean_variable
-		{
-			$$ = dfilter_mknode_join($1, relation, $2, $3);
-		}
-
 	;
 
 
@@ -283,11 +271,6 @@ bytes_value:	T_VAL_BYTE_STRING
 	;
 
 
-boolean_value:	TOK_TRUE		{ $$ = dfilter_mknode_boolean_value($1); }
-	|	TOK_FALSE		{ $$ = dfilter_mknode_boolean_value($1); }
-	;
-
-
 numeric_variable:	T_FT_UINT8	{ $$ = dfilter_mknode_numeric_variable($1); }
 	|		T_FT_UINT16	{ $$ = dfilter_mknode_numeric_variable($1); }
 	|		T_FT_UINT32	{ $$ = dfilter_mknode_numeric_variable($1); }
@@ -311,9 +294,6 @@ bytes_variable:		any_variable_type T_VAL_BYTE_RANGE
 		}
 	;
 
-boolean_variable:	T_FT_BOOLEAN	{ $$ = dfilter_mknode_boolean_variable($1); }
-	;
-
 any_variable_type:	T_FT_UINT8 { $$ = $1; }
 	|		T_FT_UINT16 { $$ = $1; }
 	|		T_FT_UINT32 { $$ = $1; }
@@ -488,24 +468,6 @@ dfilter_mknode_bytes_variable(gint id, gint offset, guint length)
 }
 
 static GNode*
-dfilter_mknode_boolean_variable(gint id)
-{
-	dfilter_node	*node;
-	GNode		*gnode;
-
-	node = g_mem_chunk_alloc(global_df->node_memchunk);
-	node->ntype = variable;
-	node->elem_size = sizeof(guint32);
-	node->fill_array_func = fill_array_boolean_variable; /* cheating ! */
-	node->check_relation_func = check_relation_boolean; /* cheating ! */
-	node->value.variable = id;
-	gnode = g_node_new(node);
-
-	gnode_slist = g_slist_append(gnode_slist, gnode);
-	return gnode;
-}
-
-static GNode*
 dfilter_mknode_numeric_value(guint32 val)
 {
 	dfilter_node	*node;
@@ -608,24 +570,6 @@ dfilter_mknode_bytes_value(GByteArray *barray)
 	return gnode;
 }
 
-static GNode*
-dfilter_mknode_boolean_value(gint truth_value)
-{
-	dfilter_node	*node;
-	GNode		*gnode;
-
-	node = g_mem_chunk_alloc(global_df->node_memchunk);
-	node->ntype = numeric;
-	node->elem_size = sizeof(guint32);
-	node->fill_array_func = fill_array_boolean_value;
-	node->check_relation_func = check_relation_boolean;
-	node->value.boolean = truth_value == TOK_TRUE ? TRUE : FALSE;
-	gnode = g_node_new(node);
-
-	gnode_slist = g_slist_append(gnode_slist, gnode);
-	return gnode;
-}
-
 static guint32
 string_to_value(char *s)
 {
diff --git a/dfilter-scanner.l b/dfilter-scanner.l
index 53b1b13f25..cfbf9db3c3 100644
--- a/dfilter-scanner.l
+++ b/dfilter-scanner.l
@@ -3,7 +3,7 @@
 /* dfilter-scanner.l
  * Scanner for display filters
  *
- * $Id: dfilter-scanner.l,v 1.10 1999/08/20 21:19:27 gram Exp $
+ * $Id: dfilter-scanner.l,v 1.11 1999/08/27 19:27:10 gram Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -105,9 +105,6 @@ ge|\>\=		{ dfilter_lval.operand = TOK_GE; return TOK_GE; }
 lt|\<		{ dfilter_lval.operand = TOK_LT; return TOK_LT; }
 le|\<\=		{ dfilter_lval.operand = TOK_LE; return TOK_LE; }
 
-true		{ dfilter_lval.operand = TOK_TRUE; return TOK_TRUE; }
-false		{ dfilter_lval.operand = TOK_FALSE; return TOK_FALSE; }
-
 \[{whitespace}*-?[0-9]+{whitespace}*:{whitespace}*[0-9]+{whitespace}*\] { /* range [ x : y ] */
 
 	char	*byterange_string = g_strdup(yytext);
diff --git a/doc/ethereal.pod.template b/doc/ethereal.pod.template
index 290e06dbcc..d41df0fccf 100644
--- a/doc/ethereal.pod.template
+++ b/doc/ethereal.pod.template
@@ -411,7 +411,7 @@ either through C-like symbols, or through English-like abbreviations:
 Furthermore, each protocol field is typed. The types are:
 
     Unsigned integer (either 8-bit, 16-bit, or 32-bit)
-    Boolean (true or false)
+    Boolean
     Ethernet address (6 bytes)
     Byte string (n-number of bytes)
     IPv4 address
@@ -424,10 +424,17 @@ three display filters are equivalent:
     frame.pkt_len > 012
     frame.pkt_len > 0xa
 
-Boolean values are either true or false. For example, a token-ring packet's source route
-field is boolean:
+Boolean values are either true or false. However, a boolean field is present in a
+protocol decode only if its value is true. If the value is false, the field is not presence.
+You can therefore check the truth value of a boolean field by simply checking for its
+existence, that is, by naming the field.  For example, a token-ring packet's source route
+field is boolean. To find any source-routed packets, the display filter is simply:
 
-    tr.sr == true
+    tr.sr
+
+Non source-routed packets can be found with the negation of that filter:
+
+    ! tr.sr
 
 Ethernet addresses, as well as a string of bytes, are represented in hex digits. The hex
 digits may be separated by colons, periods, or hyphens:
diff --git a/doc/proto_tree b/doc/proto_tree
index 3b61d3fa25..12d322b89e 100644
--- a/doc/proto_tree
+++ b/doc/proto_tree
@@ -1,4 +1,4 @@
-$Id: proto_tree,v 1.3 1999/07/15 15:33:09 gram Exp $
+$Id: proto_tree,v 1.4 1999/08/27 19:27:22 gram Exp $
 
 The Ethereal Protocol Tree
 ==========================
@@ -154,6 +154,7 @@ enum ftenum {
         FT_UINT8,
         FT_UINT16,
         FT_UINT32,
+	FT_BOOLEAN,
         FT_ABSOLUTE_TIME,
         FT_RELATIVE_TIME,
         FT_STRING,
diff --git a/packet-tr.c b/packet-tr.c
index 62ab02f32e..fa7023f763 100644
--- a/packet-tr.c
+++ b/packet-tr.c
@@ -2,7 +2,7 @@
  * Routines for Token-Ring packet disassembly
  * Gilbert Ramirez <gram@verdict.uthscsa.edu>
  *
- * $Id: packet-tr.c,v 1.22 1999/08/27 19:15:38 gram Exp $
+ * $Id: packet-tr.c,v 1.23 1999/08/27 19:27:11 gram Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@unicom.net>
@@ -434,7 +434,9 @@ dissect_tr(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
 
 		proto_tree_add_item(tr_tree, hf_tr_dst, offset + 2, 6, trn_dhost);
 		proto_tree_add_item(tr_tree, hf_tr_src, offset + 8, 6, trn_shost);
-		proto_tree_add_item_hidden(tr_tree, hf_tr_sr, offset + 8, 1, source_routed);
+
+		if (source_routed)
+			proto_tree_add_item_hidden(tr_tree, hf_tr_sr, offset + 8, 1, source_routed);
 
 		/* non-source-routed version of src addr */
 		proto_tree_add_item_hidden(tr_tree, hf_tr_src, offset + 8, 6, trn_shost_nonsr);