Merge pull request #145 from zhaozhiwen/fix/130-physlist-null-check

Null-check physics list before dereferencing it

Author: maureeungaro

gemc/gphysics/gphysics.cc

@@ -56,12 +56,12 @@ GPhysics::GPhysics(const std::shared_ptr<GOptions>& gopts) :
 
 	physList = factory.GetReferencePhysList(g4physList);
 
+	if (!physList) { log->error(ERR_PHYSLISTERROR, "physics list <" + gphysList + "> could not be loaded."); }
+
 	// Register step limiters (module default add-on).
 	// This is intentionally registered even when users select a standard reference list.
 	physList->RegisterPhysics(new G4StepLimiterPhysics());
 
-	if (!physList) { log->error(ERR_PHYSLISTERROR, "physics list <" + gphysList + "> could not be loaded."); }
-
 	log->info(2, "G4PhysListFactory: <" + g4physList + "> loaded.");
 }