From 9683dee1fe7d891f15bb64dd15f8d19cb4df434d Mon Sep 17 00:00:00 2001
From: Giulio Eulisse <10544+ktf@users.noreply.github.com>
Date: Tue, 28 Jan 2025 09:38:31 +0100
Subject: [PATCH] DPL: avoid asserting the workflow is empty

This is a property that depends on user input, so an empty workflow is actually
possible and should be handled. This currently breaks if the empty workflow is
provided in debug mode.
---
 Framework/Core/src/DeviceSpecHelpers.cxx | 4 ++++
 Framework/Core/src/WorkflowHelpers.cxx   | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Framework/Core/src/DeviceSpecHelpers.cxx b/Framework/Core/src/DeviceSpecHelpers.cxx
index f2644ed66ba08..ec0a40e44ac31 100644
--- a/Framework/Core/src/DeviceSpecHelpers.cxx
+++ b/Framework/Core/src/DeviceSpecHelpers.cxx
@@ -1118,6 +1118,10 @@ void DeviceSpecHelpers::dataProcessorSpecs2DeviceSpecs(const WorkflowSpec& workf
 {
   // Always check for validity of the workflow before instanciating it
   DeviceSpecHelpers::validate(workflow);
+  // In case the workflow is empty, we simply do not need to instanciate any device.
+  if (workflow.empty()) {
+    return;
+  }
   std::vector<LogicalForwardInfo> availableForwardsInfo;
   std::vector<DeviceConnectionEdge> logicalEdges;
   std::vector<DeviceConnectionId> connections;
diff --git a/Framework/Core/src/WorkflowHelpers.cxx b/Framework/Core/src/WorkflowHelpers.cxx
index 597f3d32856c1..b18b559fe99fb 100644
--- a/Framework/Core/src/WorkflowHelpers.cxx
+++ b/Framework/Core/src/WorkflowHelpers.cxx
@@ -756,7 +756,10 @@ void WorkflowHelpers::constructGraph(const WorkflowSpec& workflow,
                                      std::vector<OutputSpec>& outputs,
                                      std::vector<LogicalForwardInfo>& forwardedInputsInfo)
 {
-  assert(!workflow.empty());
+  // In case the workflow is empty, we do not have anything to do.
+  if (workflow.empty()) {
+    return;
+  }
 
   // This is the state. Oif is the iterator I use for the searches.
   std::vector<LogicalOutputInfo> availableOutputsInfo;