From a5680ac5f04a34a8f8abe23c738d200b73e32035 Mon Sep 17 00:00:00 2001
From: m4b <m4b.github.io@gmail.com>
Date: Sun, 17 Nov 2024 22:12:40 -0800
Subject: [PATCH] derive: fix array with a nested preadable type; add test for
 regression (#109)

---
 scroll_derive/src/lib.rs     | 14 +-------------
 scroll_derive/tests/tests.rs | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/scroll_derive/src/lib.rs b/scroll_derive/src/lib.rs
index a5714dd..11bc081 100644
--- a/scroll_derive/src/lib.rs
+++ b/scroll_derive/src/lib.rs
@@ -14,18 +14,6 @@ fn impl_field(
     let default_ctx = syn::Ident::new("ctx", proc_macro2::Span::call_site()).into_token_stream();
     let ctx = custom_ctx.unwrap_or(&default_ctx);
     match *ty {
-        syn::Type::Array(ref array) => match array.len {
-            syn::Expr::Lit(syn::ExprLit {
-                lit: syn::Lit::Int(ref int),
-                ..
-            }) => {
-                let size = int.base10_parse::<usize>().unwrap();
-                quote! {
-                    #ident: { let mut __tmp: #ty = [0u8.into(); #size]; src.gread_inout_with(offset, &mut __tmp, #ctx)?; __tmp }
-                }
-            }
-            _ => panic!("Pread derive with bad array constexpr"),
-        },
         syn::Type::Group(ref group) => impl_field(ident, &group.elem, custom_ctx),
         _ => {
             quote! {
@@ -114,7 +102,7 @@ fn impl_struct(
             syn::GenericParam::Type(ref t) => {
                 let ident = &t.ident;
                 quote! {
-                    #ident : ::scroll::ctx::TryFromCtx<'a, ::scroll::Endian> + ::std::convert::From<u8> + ::std::marker::Copy,
+                    #ident : ::scroll::ctx::TryFromCtx<'a, ::scroll::Endian, Error = ::scroll::Error> + ::std::marker::Copy,
                     ::scroll::Error : ::std::convert::From<< #ident as ::scroll::ctx::TryFromCtx<'a, ::scroll::Endian>>::Error>,
                     < #ident as ::scroll::ctx::TryFromCtx<'a, ::scroll::Endian>>::Error : ::std::convert::From<scroll::Error>
                 }
diff --git a/scroll_derive/tests/tests.rs b/scroll_derive/tests/tests.rs
index 14dec4e..d9a781e 100644
--- a/scroll_derive/tests/tests.rs
+++ b/scroll_derive/tests/tests.rs
@@ -180,7 +180,6 @@ struct Data8<T, Y> {
     ids: [T; 3],
     xyz: Y,
 }
-
 #[test]
 fn test_generics() {
     let mut bytes = [0xde, 0xed, 0xef, 0x10, 0x10];
@@ -269,3 +268,17 @@ fn test_custom_ctx_derive() {
     };
     assert_eq!(data3, bytes.ioread_with(LE).unwrap());
 }
+
+#[derive(Debug, Pread, SizeWith)]
+struct Data12 {
+    ids: [Data11; 1],
+}
+
+#[test]
+fn test_array_with_nested_pread_data() {
+    let bytes = [0xde, 0xed, 0xef, 0x10, 0x10, 0x01];
+    let data: Data12 = bytes.pread_with(0, LE).unwrap();
+    assert_eq!(data.ids[0].a, 0xedde);
+    assert_eq!(data.ids[0].b, 0x10ef);
+    assert_eq!(data.ids[0].c, 0x1001);
+}