From ff05fef19368df3ad090bb72a174e3d6897ed614 Mon Sep 17 00:00:00 2001
From: Qiyu Yan <yanqiyu17@mails.ucas.ac.cn>
Date: Tue, 17 Sep 2024 21:44:16 +0800
Subject: [PATCH] Workaround a memory leak with old ROOT IO

---
 src/Framework/Ntuple/LinkDef.h            |  2 +-
 src/Framework/Ntuple/NtpMCEventRecord.cxx | 27 +++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/Framework/Ntuple/LinkDef.h b/src/Framework/Ntuple/LinkDef.h
index 7c2dd9268c..0e10c24e83 100644
--- a/src/Framework/Ntuple/LinkDef.h
+++ b/src/Framework/Ntuple/LinkDef.h
@@ -12,7 +12,7 @@
 #pragma link C++ class genie::NtpMCJobConfig;
 #pragma link C++ class genie::NtpMCRecHeader;
 #pragma link C++ class genie::NtpMCRecordI;
-#pragma link C++ class genie::NtpMCEventRecord;
+#pragma link C++ class genie::NtpMCEventRecord-;
 #pragma link C++ class genie::NtpWriter;
 
 #endif
diff --git a/src/Framework/Ntuple/NtpMCEventRecord.cxx b/src/Framework/Ntuple/NtpMCEventRecord.cxx
index edf8fe9918..e8bfdcdb40 100644
--- a/src/Framework/Ntuple/NtpMCEventRecord.cxx
+++ b/src/Framework/Ntuple/NtpMCEventRecord.cxx
@@ -10,6 +10,7 @@
 
 #include "Framework/EventGen/EventRecord.h"
 #include "Framework/Messenger/Messenger.h"
+#include "TBuffer.h"
 #include "Framework/Ntuple/NtpMCEventRecord.h"
 
 using std::endl;
@@ -75,3 +76,29 @@ void NtpMCEventRecord::Clear(Option_t * /*opt*/)
   this->hdr.ievent = 0;
 }
 //____________________________________________________________________________
+
+// Extracted from the code ROOT generated
+// added check-and-delete before streaming to
+// avoid memory leak
+void NtpMCEventRecord::Streamer(TBuffer &R__b) {
+  // Stream an object of class genie::NtpMCEventRecord.
+
+  UInt_t R__s, R__c;
+  if (R__b.IsReading()) {
+    Version_t R__v = R__b.ReadVersion(&R__s, &R__c);
+    if (R__v) {
+    }
+    genie::NtpMCRecordI::Streamer(R__b);
+    if (event) {
+      delete event;
+      event = nullptr;
+    }
+    R__b >> event;
+    R__b.CheckByteCount(R__s, R__c, ::genie::NtpMCEventRecord::IsA());
+  } else {
+    R__c = R__b.WriteVersion(::genie::NtpMCEventRecord::IsA(), kTRUE);
+    genie::NtpMCRecordI::Streamer(R__b);
+    R__b << event;
+    R__b.SetByteCount(R__c, kTRUE);
+  }
+}
\ No newline at end of file