From 663f8d1a96b2b3b55b6eb7969036a5720b88fa91 Mon Sep 17 00:00:00 2001
From: Jonas Rembser <jonas.rembser@cern.ch>
Date: Mon, 17 Nov 2025 11:56:10 +0100
Subject: [PATCH] [RF] Avoid resetting the workspace of ModelConfig in
 HistFactory

Re-setting the workspace can be dangerous for IO reasons, and this is
why the new ROOT now emits a warning when this happens.

There is one place in HistFactory that triggered this warning, where the
Workspace was redundantly set in the constructor and with the
`ModelConfig::SetWorkspace()` function, with the same workspace.
---
 roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx | 1 -
 1 file changed, 1 deletion(-)

diff --git a/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx b/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
index 1a2fd3a311711..f5d9a473ffcf5 100644
--- a/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
+++ b/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
@@ -797,7 +797,6 @@ RooArgList HistoToWorkspaceFactoryFast::createObservables(const TH1 *hist, RooWo
     auto protoOwner = std::make_unique<RooWorkspace>(channel_name.c_str(), (channel_name+" workspace").c_str());
     RooWorkspace &proto = *protoOwner;
     auto proto_config = make_unique<ModelConfig>("ModelConfig", &proto);
-    proto_config->SetWorkspace(proto);
 
     // preprocess functions
     for(auto const& func : fPreprocessFunctions){