From 994960627bf75bf7a380f0540a60966700146dfd Mon Sep 17 00:00:00 2001
From: "alexey.lysiuk" <alexey.lysiuk@gmail.com>
Date: Mon, 21 Oct 2019 15:54:13 +0300
Subject: [PATCH] - added explicit clearing of global VM stask

When exception is thrown from JITed code, VM stask isn't cleared during unwinding
It needs to be clear explicitly to avoid memory leaks and references to destructed objects on shutdown

https://forum.zdoom.org/viewtopic.php?t=66172
---
 src/d_main.cpp               | 1 +
 src/playsim/dthinker.cpp     | 1 +
 src/scripting/vm/vm.h        | 2 ++
 src/scripting/vm/vmframe.cpp | 8 ++++++++
 4 files changed, 12 insertions(+)

diff --git a/src/d_main.cpp b/src/d_main.cpp
index d4003fbd23..90efa16ab5 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -984,6 +984,7 @@ void D_ErrorCleanup ()
 	}
 	if (gamestate == GS_INTERMISSION) gamestate = GS_DEMOSCREEN;
 	insave = false;
+	ClearGlobalVMStack();
 }
 
 //==========================================================================
diff --git a/src/playsim/dthinker.cpp b/src/playsim/dthinker.cpp
index 8ef9659e59..16b7f666fc 100644
--- a/src/playsim/dthinker.cpp
+++ b/src/playsim/dthinker.cpp
@@ -250,6 +250,7 @@ void FThinkerCollection::DestroyAllThinkers()
 	GC::FullGC();
 	if (error)
 	{
+		ClearGlobalVMStack();
 		I_Error("DestroyAllThinkers failed");
 	}
 }
diff --git a/src/scripting/vm/vm.h b/src/scripting/vm/vm.h
index 49bb51704a..db55dce43c 100644
--- a/src/scripting/vm/vm.h
+++ b/src/scripting/vm/vm.h
@@ -110,6 +110,8 @@ public:
 void ThrowAbortException(EVMAbortException reason, const char *moreinfo, ...);
 void ThrowAbortException(VMScriptFunction *sfunc, VMOP *line, EVMAbortException reason, const char *moreinfo, ...);
 
+void ClearGlobalVMStack();
+
 struct VMReturn
 {
 	void *Location;
diff --git a/src/scripting/vm/vmframe.cpp b/src/scripting/vm/vmframe.cpp
index f8916e94a8..7c2a63b1f7 100644
--- a/src/scripting/vm/vmframe.cpp
+++ b/src/scripting/vm/vmframe.cpp
@@ -715,6 +715,14 @@ void ThrowVMException(VMException *x)
 #endif
 
 
+void ClearGlobalVMStack()
+{
+	while (GlobalVMStack.PopFrame() != nullptr)
+	{
+	}
+}
+
+
 ADD_STAT(VM)
 {
 	double added = 0;