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

[ananas-block]

Summary by CodeRabbit

• Bug Fixes

  • Ensured batched address creation uses a single, consistent index so related addresses reference the same account, preventing mismatched derivations.
  • Strengthened validation to require the queue index to match the merkle-tree index and to reject operations when they differ.
  • Fixed assigned address index handling to respect the provided merkle-tree index instead of defaulting to zero.

• Tests

  • Updated tests and assertions to reflect the new index-consistency behavior.

[coderabbitai]

📝 Walkthrough

Walkthrough

BatchedAddressTree path: compute the tree index into a local variable, assign both tree_index and queue_index from it, and add a validation that address_queue_index == address_merkle_tree_account_index, returning SystemProgramError::AddressMerkleTreeAccountDiscriminatorMismatch if they differ. In zero-copy packing, address_queue_account_index is initialized from address_merkle_tree_account_index instead of 0. Tests updated accordingly.

Changes

Cohort / File(s)	Summary
Batched address derivation programs/system/src/processor/create_address_cpi_data.rs	Compute local tree_index and set both tree_index and queue_index from it; add guard ensuring address_queue_index == address_merkle_tree_account_index, returning AddressMerkleTreeAccountDiscriminatorMismatch on mismatch.
Zero-copy assignment update program-libs/compressed-account/src/instruction_data/zero_copy_set.rs	Change address_queue_account_index initialization to use provided address_merkle_tree_account_index (was constant 0) for v2 address trees; packing logic otherwise unchanged.
Tests updated to match new invariant program-libs/compressed-account/tests/zero_copy_set.rs	Adjust expectations: address_queue_account_index now mirrors address_merkle_tree_account_index (e.g., 10, 20, 30 in successive sets) instead of remaining 0; assertions and commentary updated accordingly.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested labels

ai-review

Suggested reviewers

• sergeytimoshin
• SwenSchaeferjohann

Poem

Two indices now share one small seed,
A local value guides their deed.
A sentinel checks they match in line,
So Merkle queues and trees align. 🌲✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding validation to assert that tree and queue indices match in batched address tree initialization.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 70.00%.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch jorrit/fix-batched-address-tree-init

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@programs/system/src/processor/create_address_cpi_data.rs`:
- Around line 86-94: Move the index-equality validation for batched address
trees to run immediately on entering the BatchedAddressTree match arm (i.e.,
before calling get_index_or_insert, set_address_fee, or
insert_address_sequence_number): check that
new_address_params.address_queue_index() ==
new_address_params.address_merkle_tree_account_index() and return an appropriate
error on mismatch. Replace or clarify the current
AddressMerkleTreeAccountDiscriminatorMismatch usage—either use a new error
variant like AddressQueueIndexMismatch or add a comment/documentation in the
error definition explaining the reuse—so the intent is clear when locating the
check in the BatchedAddressTree branch.

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ℹ️ Review info

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between b5f7f10 and ad0d643.

📒 Files selected for processing (1)

• programs/system/src/processor/create_address_cpi_data.rs

[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

program-libs/compressed-account/tests/zero_copy_set.rs (1)

39-39: ⚠️ Potential issue | 🟡 Minor

Update the header docstring to reflect the new invariant.

The docstring still states "Invariant: address queue account index always 0", but the actual invariant (as documented in the updated test at lines 583-584) is now address_queue_account_index == address_merkle_tree_account_index. This mismatch will confuse future readers.

📝 Proposed fix

-///    - Invariant: address queue account index always 0
+///    - Invariant: address queue account index equals address merkle tree account index (v2 batched trees)

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@program-libs/compressed-account/tests/zero_copy_set.rs` at line 39, Update
the header docstring in zero_copy_set.rs to replace the outdated invariant text
"Invariant: address queue account index always 0" with the new invariant
"Invariant: address_queue_account_index == address_merkle_tree_account_index" so
the comment matches the actual test logic; locate the header comment near the
top of the file and modify the string accordingly, ensuring the exact symbol
names address_queue_account_index and address_merkle_tree_account_index are used
in the docstring.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Outside diff comments:
In `@program-libs/compressed-account/tests/zero_copy_set.rs`:
- Line 39: Update the header docstring in zero_copy_set.rs to replace the
outdated invariant text "Invariant: address queue account index always 0" with
the new invariant "Invariant: address_queue_account_index ==
address_merkle_tree_account_index" so the comment matches the actual test logic;
locate the header comment near the top of the file and modify the string
accordingly, ensuring the exact symbol names address_queue_account_index and
address_merkle_tree_account_index are used in the docstring.

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ℹ️ Review info

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d8620fe and a0783bd.

⛔ Files ignored due to path filters (1)

• sdk-tests/csdk-anchor-full-derived-test/tests/integration_tests.rs is excluded by none and included by none

📒 Files selected for processing (1)

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