lang: Fix using owner constraint with Boxed accounts (#3087)

CHANGELOG.md

@@ -25,6 +25,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - lang: Make stack frames slimmer on ATA creation ([#3065](https://github.com/coral-xyz/anchor/pull/3065)).
 - lang: Remove `getrandom` dependency ([#3072](https://github.com/coral-xyz/anchor/pull/3072)).
 - lang: Make `InitSpace` support unnamed & unit structs ([#3084](https://github.com/coral-xyz/anchor/pull/3084)).
+- lang: Fix using `owner` constraint with `Box`ed accounts ([#3087](https://github.com/coral-xyz/anchor/pull/3087)).
 
 ### Breaking
 

lang/syn/src/codegen/accounts/constraints.rs

@@ -303,16 +303,24 @@ pub fn generate_constraint_raw(ident: &Ident, c: &ConstraintRaw) -> proc_macro2:
 
 pub fn generate_constraint_owner(f: &Field, c: &ConstraintOwner) -> proc_macro2::TokenStream {
     let ident = &f.ident;
+    let maybe_deref = match &f.ty {
+        Ty::Account(AccountTy { boxed, .. })
+        | Ty::InterfaceAccount(InterfaceAccountTy { boxed, .. }) => *boxed,
+        _ => false,
+    }
+    .then(|| quote!(*))
+    .unwrap_or_default();
     let owner_address = &c.owner_address;
     let error = generate_custom_error(
         ident,
         &c.error,
         quote! { ConstraintOwner },
         &Some(&(quote! { *my_owner }, quote! { owner_address })),
     );
+
     quote! {
         {
-            let my_owner = AsRef::<AccountInfo>::as_ref(&#ident).owner;
+            let my_owner = AsRef::<AccountInfo>::as_ref(& #maybe_deref #ident).owner;
             let owner_address = #owner_address;
             if my_owner != &owner_address {
                 return #error;

tests/misc/programs/misc/src/context.rs

@@ -1,4 +1,5 @@
 use crate::account::*;
+use crate::program::Misc;
 use anchor_lang::prelude::*;
 use anchor_spl::associated_token::AssociatedToken;
 use anchor_spl::token::{Mint, Token, TokenAccount};
@@ -803,3 +804,11 @@ pub struct InitManyAssociatedTokenAccounts<'info> {
     pub token_program: Program<'info, Token>,
     pub associated_token_program: Program<'info, AssociatedToken>,
 }
+
+#[derive(Accounts)]
+pub struct TestBoxedOwnerConstraint<'info> {
+    // Redundant check to test compilation
+    #[account(owner = program.key())]
+    pub my_account: Box<Account<'info, Data>>,
+    pub program: Program<'info, Misc>,
+}

tests/misc/programs/misc/src/lib.rs

@@ -386,10 +386,14 @@ pub mod misc {
         Ok(())
     }
 
-    #[allow(unused_variables)]
     pub fn test_init_many_associated_token_accounts(
         _ctx: Context<InitManyAssociatedTokenAccounts>,
     ) -> Result<()> {
         Ok(())
     }
+
+    /// Compilation test for https://github.com/coral-xyz/anchor/issues/3074
+    pub fn test_boxed_owner_constraint(_ctx: Context<TestBoxedOwnerConstraint>) -> Result<()> {
+        Ok(())
+    }
 }