From 010b00f3495b14f282d7b91f0d959915cd225fae Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Tue, 21 Apr 2026 14:31:53 -0700
Subject: [PATCH] take Lis index from rd in copy_var (#3298)

---
 src/machine/copier.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/machine/copier.rs b/src/machine/copier.rs
index dec0f427..e6ce699c 100644
--- a/src/machine/copier.rs
+++ b/src/machine/copier.rs
@@ -384,7 +384,6 @@ impl<T: CopierTarget> CopyTermState<T> {
     }
 
     fn copy_var(&mut self, addr: HeapCellValue) -> Result<(), AllocError> {
-        let index = addr.get_value() as usize;
         let rd = self.target.deref(addr);
         let ra = self.target.store(rd);
 
@@ -397,6 +396,7 @@ impl<T: CopierTarget> CopyTermState<T> {
                 }
             }
             (HeapCellValueTag::Lis, h) => {
+		let index = rd.get_value() as usize;
                 if h >= self.old_h && self.target[index].get_mark_bit() {
                     *self.value_at_scan() = heap_loc_as_cell!(
                         if ra.get_forwarding_bit() {
-- 
2.54.0