Fix String roundtrip with interior nul bytes

crates/napi/src/bindgen_runtime/js_values/string.rs

@@ -2,7 +2,6 @@ use crate::{bindgen_prelude::*, check_status, sys, Error, Result, Status};
 
 use std::ffi::{c_void, CStr};
 use std::fmt::Display;
-#[cfg(feature = "latin1")]
 use std::mem;
 use std::ops::Deref;
 use std::ptr;
@@ -53,12 +52,15 @@ impl FromNapiValue for String {
       "Failed to convert napi `string` into rust type `String`"
     )?;
 
-    match unsafe { CStr::from_ptr(buf_ptr) }.to_str() {
+    let mut ret = mem::ManuallyDrop::new(ret);
+    let buf_ptr = ret.as_mut_ptr();
+    let bytes = unsafe { Vec::from_raw_parts(buf_ptr as *mut u8, written_char_count, len) };
+    match String::from_utf8(bytes) {
       Err(e) => Err(Error::new(
         Status::InvalidArg,
         format!("Failed to read utf8 string, {}", e),
       )),
-      Ok(s) => Ok(s.to_owned()),
+      Ok(s) => Ok(s),
     }
   }
 }