From 321d948f8d73f0267293ea54c2da4f4262678856 Mon Sep 17 00:00:00 2001
From: Ben Lubar <ben.lubar@gmail.com>
Date: Mon, 3 Feb 2020 20:21:10 -0600
Subject: [PATCH] Fix crash on missing symbols.

Fixes #1487.
---
 library/LuaTools.cpp        | 4 ++++
 library/include/MemAccess.h | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/library/LuaTools.cpp b/library/LuaTools.cpp
index 3ac52bf45..0b6065940 100644
--- a/library/LuaTools.cpp
+++ b/library/LuaTools.cpp
@@ -1922,6 +1922,10 @@ static void Lua::Core::InitCoreContext()
 
 void DFHack::Lua::Core::Reset(color_ostream &out, const char *where)
 {
+    // This can happen if DFHack fails to initialize.
+    if (!State)
+        return;
+
     int top = lua_gettop(State);
 
     if (top != 0)
diff --git a/library/include/MemAccess.h b/library/include/MemAccess.h
index 7f3be74df..af1e250d2 100644
--- a/library/include/MemAccess.h
+++ b/library/include/MemAccess.h
@@ -254,7 +254,8 @@ namespace DFHack
             };
 
             void ValidateDescriptionOS() {
-                my_descriptor->ValidateOS();
+                if (my_descriptor)
+                    my_descriptor->ValidateOS();
             };
 
             uintptr_t getBase();