capture_info: Fix initialization of packet counter

g_hash_table_destroy will crash, if it is called on
 non-initialized memory. For some reason, this does not happen
 with other glib lists (e.g. GList seems to guard cleanly).

 This change initializes at the earliest possible time the
 packet counter hash with NULL

Change-Id: Ice66652fc9639d10b49d006ecbe80efe3f41e2ff
Reviewed-on: https://code.wireshark.org/review/12841
Reviewed-by: Roland Knall <rknall@gmail.com>
Petri-Dish: Stig Bjørlykke <stig@bjorlykke.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Stig Bjørlykke <stig@bjorlykke.org>

tshark.c

@@ -2564,6 +2564,9 @@ capture(void)
   fflush(stderr);
   g_string_free(str, TRUE);
 
+  /* initialize the counts hash with null */
+  global_info_data.counts.counts_hash = NULL;
+
   ret = sync_pipe_start(&global_capture_opts, &global_capture_session, &global_info_data, NULL);
 
   if (!ret)

ui/gtk/main.c

@@ -3181,6 +3181,9 @@ main(int argc, char *argv[])
     /* the window can be sized only, if it's not already shown, so do it now! */
     main_load_window_geometry(top_level);
 
+    /* initialize the packet counters */
+    global_info_data.counts.counts_hash = NULL;
+
     g_timeout_add(info_update_freq, resolv_update_cb, NULL);
 
     /* If we were given the name of a capture file, read it in now;

ui/qt/main_window.cpp

@@ -612,6 +612,9 @@ MainWindow::MainWindow(QWidget *parent) :
     plugin_if_register_gui_cb(PLUGIN_IF_PREFERENCE_SAVE, plugin_if_mainwindow_preference);
     plugin_if_register_gui_cb(PLUGIN_IF_GOTO_FRAME, plugin_if_mainwindow_gotoframe);
 
+    /* Initialize packet counter */
+    info_data_.counts.counts_hash = NULL;
+
     main_ui_->mainStack->setCurrentWidget(main_welcome_);
 }