stat_tap_table_ui: create tables only once during init

If you load a capture file and open any statistics dialog, you'll see the
list of collected items. Each time you press the Apply button (without entering a
display filter) another list of items will be created as a top-level entry
of the statistics tree. Only the first list will have the correct values,
all subsequent lists will not be populated.

Each statistic module defines a stat_tap_table_ui structure that contains a
stat_tap_init_cb function. This init function is called by
SimpleStatisticsDialog::fillTree before the tap listener is registered. This
happens each time we collect the statistics.

However, it seems that all init functions create a new stat_tap_table each
time they are called, even if they already have an existing stat_tap_table
of the same name.

This patch adds a stat_tap_find_table function to find a table by name.

As a first step, we update the ANSI A-I/F BSMAP Statistics to check if its
table is already registered. If it is, the table will not be created again.

debian/libwireshark0.symbols

@@ -1519,6 +1519,7 @@ libwireshark.so.0 libwireshark0 #MINVER#
  stat_node_array_sortcmp@Base 1.12.0~rc1
  stat_tap_add_table@Base 2.5.1
  stat_tap_by_name@Base 2.5.1
+ stat_tap_find_table@Base 3.5.0
  stat_tap_get_field_data@Base 2.5.1
  stat_tap_get_filter@Base 2.5.1
  stat_tap_init_table@Base 2.5.1

epan/dissectors/packet-ansi_a.c

@@ -10643,14 +10643,19 @@ static stat_tap_table_item bsmap_stat_fields[] = {{TABLE_ITEM_UINT, TAP_ALIGN_RI
 
 static void ansi_a_bsmap_stat_init(stat_tap_table_ui* new_stat)
 {
+    const char *table_name = "ANSI A-I/F BSMAP Statistics";
     int num_fields = sizeof(bsmap_stat_fields)/sizeof(stat_tap_table_item);
-    stat_tap_table* table = stat_tap_init_table("ANSI A-I/F BSMAP Statistics", num_fields, 0, NULL);
+    stat_tap_table *table;
     int i = 0;
     stat_tap_table_item_type items[sizeof(bsmap_stat_fields)/sizeof(stat_tap_table_item)];
 
-    stat_tap_add_table(new_stat, table);
+    table = stat_tap_find_table(new_stat, table_name);
+    if (!table) {
+        table = stat_tap_init_table(table_name, num_fields, 0, NULL);
+        stat_tap_add_table(new_stat, table);
+    }
 
-    /* Add a fow for each value type */
+    /* Add a row for each value type */
     while (ansi_a_bsmap_strings[i].strptr)
     {
         items[IEI_COLUMN].type = TABLE_ITEM_UINT;

epan/stat_tap_ui.c

@@ -192,6 +192,24 @@ stat_tap_table* stat_tap_init_table(const char *name, int num_fields, int num_el
     return new_table;
 }
 
+stat_tap_table *stat_tap_find_table(stat_tap_table_ui *ui, const char *name)
+{
+    guint i = 0;
+    stat_tap_table *stat_table;
+
+    if (ui->tables == NULL)
+        return NULL;
+
+    for (i = 0; i < ui->tables->len; i++) {
+        stat_table = g_array_index(ui->tables, stat_tap_table *, i);
+        if (!g_strcmp0(stat_table->title, name)) {
+            return stat_table;
+        }
+    }
+
+    return NULL;
+}
+
 void stat_tap_add_table(stat_tap_table_ui* new_stat, stat_tap_table* table)
 {
     if (new_stat->tables == NULL)

epan/stat_tap_ui.h

@@ -159,7 +159,7 @@ WS_DLL_PUBLIC void stat_tap_get_filter(stat_tap_table_ui* new_stat, const char *
 WS_DLL_PUBLIC stat_tap_table* stat_tap_init_table(const char *name, int num_fields, int num_elements,
                 const char *filter_string);
 WS_DLL_PUBLIC void stat_tap_add_table(stat_tap_table_ui* new_stat, stat_tap_table* table);
-
+WS_DLL_PUBLIC stat_tap_table *stat_tap_find_table(stat_tap_table_ui *ui, const char *name);
 WS_DLL_PUBLIC void stat_tap_init_table_row(stat_tap_table *stat_table, guint table_index, guint num_fields, const stat_tap_table_item_type* fields);
 WS_DLL_PUBLIC stat_tap_table_item_type* stat_tap_get_field_data(const stat_tap_table *stat_table, guint table_index, guint field_index);
 WS_DLL_PUBLIC void stat_tap_set_field_data(stat_tap_table *stat_table, guint table_index, guint field_index, stat_tap_table_item_type* field_data);