Rename proto_construct_dfilter_string() to

proto_construct_match_selected_string() to indicate what it does - and
have it return a Boolean indication of whether the string could be
built, returning the string through a pointer, and, if that pointer is
null, have it just return the Boolean and not construct the string.

Get rid of proto_can_match_selected() -
proto_construct_match_selected_string() can be used for that, which
means we have only one piece of code that knows whether a "match
selected" string can be constructed or not.

Have proto_construct_match_selected_string() support matching
zero-length FT_NONE (and FT_PCRE, but that shouldn't happen) fields even
if there's no epan_dissect_t, as such a match just checks whether the
field is present.

svn path=/trunk/; revision=19967

1 files changed, 6 insertions, 9 deletions

diff --git a/epan/proto.h b/epan/proto.h
index 1f8af93e2d..78c1096843 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -1532,19 +1532,16 @@ hfinfo_bitwidth(header_field_info *hfinfo);
 
 #include "epan.h"
 
-/** Can we do a "match selected" on this field.
+/** Check whether we can do a "match selected" on this field and, if
+    requested to, return the filter that does so.
  @param finfo field_info
  @param edt epan dissecting
+ @param filter if non-null, the display filter string is constructed and
+ *filter is set to point to it
  @return TRUE if we can do a "match selected" on the field, FALSE otherwise. */
 extern gboolean
-proto_can_match_selected(field_info *finfo, epan_dissect_t *edt);
-
-/** Construct a display filter string.
- @param finfo field_info
- @param edt epan dissecting
- @return the display filter string */
-extern char*
-proto_construct_dfilter_string(field_info *finfo, epan_dissect_t *edt);
+proto_construct_match_selected_string(field_info *finfo, epan_dissect_t *edt,
+    char **filter);
 
 /** Find field from offset in tvb.
  @param tree