fix: get_create_init_code can be wrong (privacy-scaling-explorations#1671)

### Description

[_PR description_]

### Issue Link

fix
privacy-scaling-explorations#1670

### Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

### Contents

- [_item_]

### Rationale

[_design decisions and extended information_]

### How Has This Been Tested?

[_explanation_]

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### Single responsability

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mandatory.

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This PR contains:
- Cleanup of xxxx, yyyy
- Changed xxxx to yyyy in order to bla bla
- Added xxxx function to ...
- Refactored ....
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### Design choices

RECOMMENDED to:
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Author: lispc

bus-mapping/src/circuit_input_builder.rs

@@ -501,21 +501,21 @@ pub fn keccak_inputs_tx_circuit(
 }
 
 /// Retrieve the init_code from memory for {CREATE, CREATE2}
-pub fn get_create_init_code<'a>(
-    call_ctx: &'a CallContext,
-    step: &GethExecStep,
-) -> Result<&'a [u8], Error> {
+pub fn get_create_init_code(call_ctx: &CallContext, step: &GethExecStep) -> Result<Vec<u8>, Error> {
     let offset = step.stack.nth_last(1)?.low_u64() as usize;
     let length = step.stack.nth_last(2)?.as_usize();
 
     let mem_len = call_ctx.memory.0.len();
-    if offset >= mem_len {
-        return Ok(&[]);
+    let mut result = vec![0u8; length];
+    if length > 0 && offset < mem_len {
+        let offset_end = offset
+            .checked_add(length)
+            .expect("overflow should be handled using OOG error")
+            .min(mem_len);
+        let copy_len = offset_end - offset;
+        result[..copy_len].copy_from_slice(&call_ctx.memory.0[offset..offset_end]);
     }
-
-    let offset_end = offset.checked_add(length).unwrap_or(mem_len);
-
-    Ok(&call_ctx.memory.0[offset..offset_end])
+    Ok(result)
 }
 
 /// Retrieve the memory offset and length of call.