From cf438d91bdeb14be803e1b35d2c92ba0ce0d24bb Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Wed, 1 Nov 2023 18:46:54 +0100
Subject: [PATCH] fix: peek returns nth element from the top of the stack
 (#5262)

---
 crates/revm/revm-inspectors/src/tracing/js/bindings.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/crates/revm/revm-inspectors/src/tracing/js/bindings.rs b/crates/revm/revm-inspectors/src/tracing/js/bindings.rs
index 25d4cfc962..fd794570c7 100644
--- a/crates/revm/revm-inspectors/src/tracing/js/bindings.rs
+++ b/crates/revm/revm-inspectors/src/tracing/js/bindings.rs
@@ -280,6 +280,7 @@ impl StackObj {
         .length(0)
         .build();
 
+        // peek returns the nth-from-the-top element of the stack.
         let peek = FunctionObjectBuilder::new(
             context,
             NativeFunction::from_copy_closure_with_captures(
@@ -293,6 +294,9 @@ impl StackObj {
                             ),
                         )))
                     }
+                    // idx is from the top of the stack, so we need to reverse it
+                    // SAFETY: bounds checked above
+                    let idx = len - idx - 1;
                     stack_arr.get(idx as u64, ctx)
                 },
                 stack_arr,