From 16c84948c2f765d95db3dbb6d96e04a35b88fd3a Mon Sep 17 00:00:00 2001
From: Giulio De Pasquale <giulio@depasquale.eu>
Date: Sat, 8 Jul 2017 23:27:38 +0200
Subject: [PATCH] =?UTF-8?q?Lo=20stack=20non=20pu=C3=B2=20andare=20sotto=20?=
 =?UTF-8?q?zero?=
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---
 vm/vm.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/vm/vm.cpp b/vm/vm.cpp
index 6c90474..aa7a0f1 100644
--- a/vm/vm.cpp
+++ b/vm/vm.cpp
@@ -617,6 +617,10 @@ bool VM::execPOOP(void) {
 
   dst = as.code[regs[IP] + 1];
   DBG_INFO(("POOP %s\n", getRegName(dst)));
+  if (regs[SP] - sizeof(uint16_t) < 0) {
+    DBG_ERROR(("Stack is going below 0!\n"));
+    return false;
+  }
   regs[SP] -= sizeof(uint16_t);
   memcpy(&regs[dst], &as.stack[regs[SP]], sizeof(uint16_t));
   return true;