From c36d4a9c9a8f2b1082aa67c7eeee9dd0e1fe5401 Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Wed, 1 Jun 2022 00:02:11 -0600
Subject: [PATCH] unmark cells in arith_eval_by_metacall (#1497)

---
 src/machine/arithmetic_ops.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/machine/arithmetic_ops.rs b/src/machine/arithmetic_ops.rs
index 2f1504b7..d77283f1 100644
--- a/src/machine/arithmetic_ops.rs
+++ b/src/machine/arithmetic_ops.rs
@@ -1128,6 +1128,8 @@ impl MachineState {
                 return Err(self.error_form(evaluable_error, stub_gen()));
             }
 
+            let value = unmark_cell_bits!(value);
+
             read_heap_cell!(value,
                 (HeapCellValueTag::Atom, (name, arity)) => {
                     if arity == 2 {
-- 
2.54.0