From 6f5bda1846ddf33d7b7931a7655068122c773bb1 Mon Sep 17 00:00:00 2001
From: Javier Galan <javier.galan@unizar.es>
Date: Wed, 1 Feb 2023 11:15:01 +0100
Subject: [PATCH] REST_Geant4_ViewGeometry.C protecting pointers

---
 macros/REST_Geant4_ViewGeometry.C | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/macros/REST_Geant4_ViewGeometry.C b/macros/REST_Geant4_ViewGeometry.C
index 3d96aa6..d6556f4 100644
--- a/macros/REST_Geant4_ViewGeometry.C
+++ b/macros/REST_Geant4_ViewGeometry.C
@@ -40,6 +40,16 @@ Int_t REST_Geant4_ViewGeometry(TString fName, TString option = "") {
         cout << "File is not supported!" << endl;
     }
 
+    if (geo == nullptr) {
+        RESTError << "Geometry initialization failed!" << RESTendl;
+        return 0;
+    }
+
+    if (geo->GetMasterVolume() == nullptr) {
+        RESTError << "No master volume found in the geometry!" << RESTendl;
+        return 0;
+    }
+
     if (option == "") {
         geo->GetMasterVolume()->Draw();
     } else if (ToUpper((string)option) == "EVE") {