transum: expert infos are not Boolean fields.

They're of type FT_NONE, meaning that they do not have values, they're
just present or not.

Handle the TCP analysis fields "tcp.analysis.retransmission" and
"tcp.analysis.keep_alive", both of which are expert infos, by just
seeing if they're present or not.

Fixes a problem mentioned in a comment in merge request !8412.

3 files changed, 39 insertions, 4 deletions

diff --git a/plugins/epan/transum/decoders.c b/plugins/epan/transum/decoders.c
index c3f8ab65f0..c430f588ec 100644
--- a/plugins/epan/transum/decoders.c
+++ b/plugins/epan/transum/decoders.c
@@ -217,14 +217,25 @@ int decode_gtcp(packet_info *pinfo, proto_tree *tree, PKT_INFO* pkt_info)
             pkt_info->tcp_flags_reset = field_bool[0];
     }
 
-    if (!extract_bool(tree, hf_of_interest[HF_INTEREST_TCP_RETRAN].hf, field_bool, &field_value_count)) {
+    /*
+     * This is an expert info, not a field with a value, so it's either
+     * present or not; if present, it's a retransmission.
+     */
+    if (!extract_instance_count(tree, hf_of_interest[HF_INTEREST_TCP_RETRAN].hf, &field_value_count)) {
         if (field_value_count)
-            pkt_info->tcp_retran = field_bool[0];
+            pkt_info->tcp_retran = TRUE;
+        else
+            pkt_info->tcp_retran = FALSE;
     }
 
-    if (!extract_bool(tree, hf_of_interest[HF_INTEREST_TCP_KEEP_ALIVE].hf, field_bool, &field_value_count)) {
+    /*
+     * Another expert info.
+     */
+    if (!extract_instance_count(tree, hf_of_interest[HF_INTEREST_TCP_KEEP_ALIVE].hf, &field_value_count)) {
         if (field_value_count)
-            pkt_info->tcp_keep_alive = field_bool[0];
+            pkt_info->tcp_retran = TRUE;
+        else
+            pkt_info->tcp_retran = FALSE;
     }
 
     /* we use the SSL Content Type to detect SSL Alerts */
diff --git a/plugins/epan/transum/extractors.c b/plugins/epan/transum/extractors.c
index cd95550528..87a6d3234f 100644
--- a/plugins/epan/transum/extractors.c
+++ b/plugins/epan/transum/extractors.c
@@ -129,6 +129,29 @@ int extract_bool(proto_tree *tree, int field_id, gboolean *result_array, size_t
 }
 
 /*
+ * Extract a count of the number of instances of a given field.
+ */
+int extract_instance_count(proto_tree *tree, int field_id, size_t *element_count)
+{
+    GPtrArray *finfo_array;
+
+    *element_count = 0;
+    if (tree == NULL) {
+        return -1;
+    }
+
+    finfo_array = proto_get_finfo_ptr_array(tree, field_id);
+
+    if (finfo_array == NULL) {
+        return -1;
+    }
+
+    *element_count = g_ptr_array_len(finfo_array);
+
+    return 0;
+}
+
+/*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *
  * Local variables:
diff --git a/plugins/epan/transum/extractors.h b/plugins/epan/transum/extractors.h
index 5bf575792f..d56134a6db 100644
--- a/plugins/epan/transum/extractors.h
+++ b/plugins/epan/transum/extractors.h
@@ -18,3 +18,4 @@ int extract_uint(proto_tree *tree, int field_id, guint32 *result_array, size_t *
 int extract_ui64(proto_tree *tree, int field_id, guint64 *result_array, size_t *element_count);
 int extract_si64(proto_tree *tree, int field_id, guint64 *result_array, size_t *element_count);
 int extract_bool(proto_tree *tree, int field_id, gboolean *result_array, size_t *element_count);
+int extract_instance_count(proto_tree *tree, int field_id, size_t *element_count);