From 82081b22062fc4fb14c791cb4e547632e20b24cd Mon Sep 17 00:00:00 2001
From: Sei Lisa <sei-lisa@email.fake>
Date: Mon, 16 Oct 2017 01:20:01 +0200
Subject: [PATCH] Fix crash when variables appear inside global lists.

Fixes #3.
---
 lslopt/lsldeadcode.py | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lslopt/lsldeadcode.py b/lslopt/lsldeadcode.py
index c5556eb..337d3b4 100644
--- a/lslopt/lsldeadcode.py
+++ b/lslopt/lsldeadcode.py
@@ -223,8 +223,19 @@ class deadcode(object):
             node['X'] = True
             if child is not None:
                 if 'orig' in child[0]:
-                    self.MarkReferences(child[0]['orig'])
-                    child[0]['X'] = child[0]['orig']['X']
+                    orig = child[0]['orig']
+                    self.MarkReferences(orig)
+                    child[0]['X'] = orig['X']
+                    if orig['nt'] == 'LIST':
+                        # Add fake writes to variables used in list elements in
+                        # 'orig', so they don't get deleted (Issue #3)
+                        for subnode in orig['ch']:
+                            if subnode['nt'] == 'IDENT':
+                                # can only happen in globals
+                                assert subnode['scope'] == 0
+                                sym = self.symtab[0][subnode['name']]
+                                sym['W'] = False
+                                self.tree[sym['Loc']]['X'] = True
                 else:
                     self.MarkReferences(child[0])
             return True