From 1748a80e84b5063ef35d2f57bcaa5fa3539221bf Mon Sep 17 00:00:00 2001
From: Vincenzo Eduardo Padulano <v.e.padulano@gmail.com>
Date: Tue, 3 Oct 2023 17:15:18 +0200
Subject: [PATCH] [df] Add regression test for #12043

---
 .../test/dataframe_definepersample.cxx         | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tree/dataframe/test/dataframe_definepersample.cxx b/tree/dataframe/test/dataframe_definepersample.cxx
index f731c2bd629ce..32a4c9076382e 100644
--- a/tree/dataframe/test/dataframe_definepersample.cxx
+++ b/tree/dataframe/test/dataframe_definepersample.cxx
@@ -157,6 +157,24 @@ TEST(DefinePerSampleMore, GetDefinedColumnNames)
    EXPECT_EQ(df.GetDefinedColumnNames(), std::vector<std::string>{"x"});
 }
 
+// Regression test for https://github.com/root-project/root/issues/12043
+TEST(DefinePerSample, TwoExecutions)
+{
+   bool flag = false;
+   auto df = ROOT::RDataFrame(1).DefinePerSample("x", [&flag](unsigned int, const ROOT::RDF::RSampleInfo &) {
+      flag = true;
+      return 0;
+   });
+   // Trigger the first execution of the event loop, the flag should be true.
+   df.Count().GetValue();
+   EXPECT_TRUE(flag);
+   // Reset the flag and trigger again, flag should be again set to true after
+   // the end of the second event loop.
+   flag = false;
+   df.Count().GetValue();
+   EXPECT_TRUE(flag);
+}
+
 /* TODO
 // Not supported yet
 TEST(DefinePerSample, DataSource)