From acc2d9a0d1ba2a2595c355073e9b3944c09b6dae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markku=20Leini=C3=B6?=
 <markkuleinio@users.noreply.github.com>
Date: Sun, 6 Aug 2023 16:51:26 +0300
Subject: [PATCH] Add existing dissector check

---
 zabbix.lua      | 15 ++++++++++++++-
 zabbixagent.lua | 15 ++++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/zabbix.lua b/zabbix.lua
index 2859f93..d722fa6 100644
--- a/zabbix.lua
+++ b/zabbix.lua
@@ -1,9 +1,22 @@
 local plugin_info = {
-    version = "2023-01-01.1",
+    version = "2023-08-06.1",
     author = "Markku Leiniö",
     repository = "https://github.com/markkuleinio/wireshark-zabbix-dissectors",
 }
 set_plugin_info(plugin_info)
+if Dissector.get("zabbix") then
+    local ignore_text = "Your Wireshark version already contains Zabbix protocol dissector compiled in. " ..
+        "Therefore the Zabbix dissector in your local Lua script is ignored:\n" ..
+        debug.getinfo(1, "S").source:sub(2) ..
+        "\nDelete/move the script to remove this message."
+    if gui_enabled() then
+        local win = TextWindow.new("Note from Zabbix Lua dissector")
+        win:set(ignore_text)
+    else
+        print(ignore_text)
+    end
+    return
+end
 local zabbix_protocol = Proto("Zabbix", "Zabbix Protocol")
 -- for some reason the protocol name is shown in UPPERCASE in Protocol column
 -- (and in Proto.name), so let's define a string to override that
diff --git a/zabbixagent.lua b/zabbixagent.lua
index d3650f9..7840a37 100644
--- a/zabbixagent.lua
+++ b/zabbixagent.lua
@@ -1,9 +1,22 @@
 local plugin_info = {
-    version = "2022-12-17.1",
+    version = "2023-08-06.1",
     author = "Markku Leiniö",
     repository = "https://github.com/markkuleinio/wireshark-zabbix-dissectors",
 }
 set_plugin_info(plugin_info)
+if Dissector.get("zabbix") or Dissector.get("zabbixagent") then
+    local ignore_text = "Your Wireshark version already contains Zabbix/ZabbixAgent protocol dissector compiled in. " ..
+        "Therefore the ZabbixAgent dissector in your local Lua script is ignored:\n" ..
+        debug.getinfo(1, "S").source:sub(2) ..
+        "\nDelete/move the script to remove this message."
+    if gui_enabled() then
+        local win = TextWindow.new("Note from ZabbixAgent Lua dissector")
+        win:set(ignore_text)
+    else
+        print(ignore_text)
+    end
+    return
+end
 local zabbixagent_protocol = Proto("ZabbixAgent", "Zabbix Agent Protocol")
 -- for some reason the protocol name is shown in UPPERCASE in Protocol column
 -- (and in Proto.name), so let's define a string to override that