fix: batched address tree init assert tree and queue index are the same

program-libs/compressed-account/src/instruction_data/zero_copy_set.rs

@@ -169,7 +169,7 @@ impl ZNewAddressParamsAssignedPackedMut<'_> {
     ) {
         self.seed = seed;
         self.address_merkle_tree_root_index = address_merkle_tree_root_index;
-        self.address_queue_account_index = 0; // always 0 for v2 address trees.
+        self.address_queue_account_index = address_merkle_tree_account_index;
         if let Some(assigned_account_index) = assigned_account_index {
             self.assigned_account_index = assigned_account_index;
             self.assigned_to_account = 1; // set to true

program-libs/compressed-account/tests/zero_copy_set.rs

@@ -539,7 +539,7 @@ fn test_new_address_set_success_with_assigned_account() {
     assert_eq!(z_new_address.assigned_account_index, 7);
     assert_eq!(z_new_address.address_merkle_tree_account_index, 10);
     assert_eq!(z_new_address.assigned_to_account, 1);
-    assert_eq!(z_new_address.address_queue_account_index, 0); // Invariant: always 0
+    assert_eq!(z_new_address.address_queue_account_index, 10);
 }
 
 #[test]
@@ -567,7 +567,7 @@ fn test_new_address_set_success_without_assigned_account() {
     assert_eq!(z_new_address.assigned_account_index, 0);
     assert_eq!(z_new_address.address_merkle_tree_account_index, 10);
     assert_eq!(z_new_address.assigned_to_account, 0);
-    assert_eq!(z_new_address.address_queue_account_index, 0); // Invariant: always 0
+    assert_eq!(z_new_address.address_queue_account_index, 10);
 }
 
 #[test]
@@ -580,16 +580,16 @@ fn test_new_address_set_invariant_address_queue_account_index() {
         NewAddressParamsAssignedPacked::zero_copy_at_mut(&mut data).unwrap();
 
     // Execute multiple times with different inputs
+    // Invariant: address_queue_account_index == address_merkle_tree_account_index
+    // for v2 batched address trees (queue is embedded in the tree account).
     z_new_address.set([1u8; 32], U16::new(100), Some(5), 10);
-    assert_eq!(z_new_address.address_queue_account_index, 0);
+    assert_eq!(z_new_address.address_queue_account_index, 10);
 
     z_new_address.set([2u8; 32], U16::new(200), None, 20);
-    assert_eq!(z_new_address.address_queue_account_index, 0);
+    assert_eq!(z_new_address.address_queue_account_index, 20);
 
     z_new_address.set([3u8; 32], U16::new(300), Some(50), 30);
-    assert_eq!(z_new_address.address_queue_account_index, 0);
-
-    // Assert invariant: address_queue_account_index always 0 for v2 address trees
+    assert_eq!(z_new_address.address_queue_account_index, 30);
 }
 
 // =============================================================================

programs/system/src/processor/create_address_cpi_data.rs

@@ -66,11 +66,13 @@ pub fn derive_new_addresses<'info, 'a, 'b: 'a, const ADDRESS_ASSIGNMENT: bool>(
                     Err(SystemProgramError::DeriveAddressError)
                 }?;
 
-                cpi_ix_data.addresses[i].tree_index = context.get_index_or_insert(
+                let tree_index = context.get_index_or_insert(
                     new_address_params.address_merkle_tree_account_index(),
                     remaining_accounts,
                     "V2 address tree",
                 )?;
+                cpi_ix_data.addresses[i].tree_index = tree_index;
+                cpi_ix_data.addresses[i].queue_index = tree_index;
 
                 context.set_address_fee(
                     tree.metadata.rollover_metadata.network_fee,
@@ -83,6 +85,16 @@ pub fn derive_new_addresses<'info, 'a, 'b: 'a, const ADDRESS_ASSIGNMENT: bool>(
                     tree.queue_batches.next_index,
                 );
 
+                // For batched address trees the queue is embedded in the tree
+                // account so both indices must point to the same account.
+                if new_address_params.address_queue_index()
+                    != new_address_params.address_merkle_tree_account_index()
+                {
+                    return Err(ProgramError::from(
+                        SystemProgramError::AddressMerkleTreeAccountDiscriminatorMismatch,
+                    ));
+                }
+
                 (
                     derive_address(
                         &new_address_params.seed(),

sdk-tests/csdk-anchor-full-derived-test/tests/integration_tests.rs

@@ -3863,7 +3863,7 @@ async fn test_d9_edge_many_literals() {
 #[tokio::test]
 async fn test_d9_edge_mixed() {
     use csdk_anchor_full_derived_test::d9_seeds::{
-        edge_cases::{AB, SEED_123, _UNDERSCORE_CONST},
+        edge_cases::{_UNDERSCORE_CONST, AB, SEED_123},
         D9EdgeMixedParams,
     };