From 0a2fb31daebd466137c77d5ebb031039efea20f4 Mon Sep 17 00:00:00 2001
From: Vlad Khorsun <hvlad@users.sourceforge.net>
Date: Thu, 11 Apr 2024 14:21:40 +0300
Subject: [PATCH 1/2] Added assert to show bug #8079

---
 src/jrd/jrd.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/jrd/jrd.cpp b/src/jrd/jrd.cpp
index 98f3900fda..d8e3a73ae7 100644
--- a/src/jrd/jrd.cpp
+++ b/src/jrd/jrd.cpp
@@ -9859,6 +9859,8 @@ void TrigVector::release()
 
 void TrigVector::release(thread_db* tdbb)
 {
+	fb_assert(useCount.value() > 0);
+
 	if (--useCount == 0)
 	{
 		decompile(tdbb);

From a580a308c6bb785dfc1ab57bb0cdd7ba3f8514a9 Mon Sep 17 00:00:00 2001
From: Vlad Khorsun <hvlad@users.sourceforge.net>
Date: Thu, 11 Apr 2024 14:22:47 +0300
Subject: [PATCH 2/2] Fixed bug #8079 :  Engine could crash when executing some
 trigger(s) while another attachment modifies them

---
 src/jrd/exe.cpp | 10 ++--------
 src/jrd/met.epp |  1 +
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/src/jrd/exe.cpp b/src/jrd/exe.cpp
index 7fef5d51b9..825b29aa41 100644
--- a/src/jrd/exe.cpp
+++ b/src/jrd/exe.cpp
@@ -1289,7 +1289,7 @@ void EXE_execute_triggers(thread_db* tdbb,
  *	if any blow up.
  *
  **************************************/
-	if (!*triggers)
+	if (!*triggers || (*triggers)->isEmpty())
 		return;
 
 	SET_TDBB(tdbb);
@@ -1297,7 +1297,7 @@ void EXE_execute_triggers(thread_db* tdbb,
 	Request* const request = tdbb->getRequest();
 	jrd_tra* const transaction = request ? request->req_transaction : tdbb->getTransaction();
 
-	TrigVector* vector = *triggers;
+	RefPtr<TrigVector> vector(*triggers);
 	Record* const old_rec = old_rpb ? old_rpb->rpb_record : NULL;
 	Record* const new_rec = new_rpb ? new_rpb->rpb_record : NULL;
 
@@ -1422,15 +1422,9 @@ void EXE_execute_triggers(thread_db* tdbb,
 
 			trigger = NULL;
 		}
-
-		if (vector != *triggers)
-			MET_release_triggers(tdbb, &vector, true);
 	}
 	catch (const Exception& ex)
 	{
-		if (vector != *triggers)
-			MET_release_triggers(tdbb, &vector, true);
-
 		if (trigger)
 		{
 			EXE_unwind(tdbb, trigger);
diff --git a/src/jrd/met.epp b/src/jrd/met.epp
index 252775860a..0f3bae45b8 100644
--- a/src/jrd/met.epp
+++ b/src/jrd/met.epp
@@ -1883,6 +1883,7 @@ void MET_load_ddl_triggers(thread_db* tdbb)
 
 	attachment->att_ddl_triggers = FB_NEW_POOL(*attachment->att_pool)
 		TrigVector(*attachment->att_pool);
+	attachment->att_ddl_triggers->addRef();
 
 	AutoRequest trigger_request;