From e0b9902cbb865ae7a7baa8e4c1f1288ecd5eed31 Mon Sep 17 00:00:00 2001
From: "Daniel R. Roe" <daniel.r.roe@gmail.com>
Date: Tue, 26 Nov 2024 09:45:07 -0500
Subject: [PATCH] Add error message for when topology is not present - needed
 for the inmask for loop

---
 src/ForLoop_mask.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/ForLoop_mask.cpp b/src/ForLoop_mask.cpp
index ccddb3ec1d..015fb3bccf 100644
--- a/src/ForLoop_mask.cpp
+++ b/src/ForLoop_mask.cpp
@@ -47,7 +47,10 @@ int ForLoop_mask::SetupFor(CpptrajState& State, ArgList& argIn) {
   }
   Topology* top = State.DSL().GetTopByIndex( argIn );
   if (top != 0) currentTop_ = top;
-  if (currentTop_ == 0) return 1;
+  if (currentTop_ == 0) {
+    mprinterr("Error: No topology found for mask for loop.\n");
+    return 1;
+  }
   // Get the variable name
   if (SetupLoopVar( State.DSL(), argIn.GetStringNext() )) return 1;