{ "number": 36583, "repo": "bitcoin/bitcoin", "url": "https://github.com/bitcoin/bitcoin/pull/36583", "title": "wallet: fix migration of watch-only wallets with transactions", "author": "yusufyildiz34", "author_association": "FIRST_TIME_CONTRIBUTOR", "created_at": "2026-10-20T12:08:50Z", "updated_at": "2026-10-26T09:52:20Z", "description_hash": "c3ef4957dd00b4ca", "age_days": 12, "draft": false, "labels": [ "Wallet" ], "milestone": null, "base": "master", "head_sha": "50f254e53ac357e5a8315062c634e36071e1aa19", "head_ref": "wallet-migration-36483", "head_repo": "yusufyildiz34/bitcoin", "head_history": [], "additions": 64, "deletions": 3, "changed_files": 5, "commit_count": 2, "size_bucket": "S", "mergeable_state": "clean", "bot": { "drahtbot": { "present": true, "reviews": { "ack": [ { "login": "Naomi-Gift", "url": "https://github.com/bitcoin/bitcoin/pull/36583#issuecomment-6334608827" } ] }, "conflicts": [] } }, "acks_parsed": { "Naomi-Gift": { "kind": "ack", "hash": "50f254e53ac357e5a8315062c634e36071e1aa19", "t": "2026-10-22T06:47:34Z", "stale": false } }, "acks_tally": { "ack": 1, "stale_ack": 0, "concept_ack": 0, "approach_ack": 0, "nack": 0, "concept_nack": 0, "approach_nack": 0 }, "reviews": { "approved": 0, "changes_requested": 0, "distinct_reviewers": [ "Naomi-Gift" ] }, "signals": { "needs_rebase": false, "ci_failed": false, "mergeable_state": "clean", "last_author_activity": "2026-10-20T11:32:00Z", "last_reviewer_activity": "2026-10-22T06:47:34Z", "last_reviewer": "Naomi-Gift", "author_silent_days": 12, "waiting_on_author_days": 10, "days_since_update": 6 }, "refs": { "mentioned": [ 36483 ], "depends_on": [], "fixes": [ 36483 ], "linked_issues": [ { "number": 36483, "type": "issue", "state": "open", "merged": false, "merged_at": null, "title": "wallet: Migration fails for legacy wallet with no keys watching an address" } ], "references": [ { "number": 36483, "type": "issue", "state": "open", "merged": false, "merged_at": null, "title": "wallet: Migration fails for legacy wallet with no keys watching an address" } ], "conflicts": [] }, "stack": { "shares_commits_with": [], "based_on": [], "base_for": [] }, "review_paths": [], "body": "Migrating a legacy wallet that holds no spendable material fails whenever the\nwallet contains transactions. `migratewallet` returns\n`std::bad_function_call (-1)` and the wallet is left unmigrated.\n\nTwo defects are involved, and the first one hides the second.\n\n### 1. The migration check reads in-memory state that has not been updated yet\n\nWhen the wallet being migrated has no spendable material,\n`CWallet::ApplyMigrationData()` asserts that nothing is left behind in it:\n\n```cpp\nif (!m_address_book.empty()) return util::Error{_(\"Error: Not all address book records were migrated\")};\nif (!mapWallet.empty()) return util::Error{_(\"Error: Not all transaction records were migrated\")};\n```\n\nThe two checks look symmetric but are not. `DelAddressBookWithDB()` erases from\n`m_address_book` straight away, so the first check sees current state.\n`RemoveTxs()` only erases the transaction records from disk; it defers the\n`mapWallet` removal to the db txn's `on_commit` listener, which does not run\nuntil the txn is committed \u2014 after `ApplyMigrationData()` has returned.\n\n`mapWallet` is therefore never empty at that point and the check always fails.\n\n### 2. Aborting the txn calls a callback that was never set\n\n`DbTxnListener` declares `on_commit` and `on_abort` as plain `std::function`\nmembers and callers may set only the one they need. `RemoveTxs()` does exactly\nthat: `on_commit` is set, `on_abort` is left empty.\n\n`TxnCommit()` and `TxnAbort()` each invoked their listener's callback\nunconditionally, so the abort triggered by the failed check above threw\n`std::bad_function_call`. The exception escaped the wallet entirely, replacing\nthe real error with an unhelpful one and skipping the caller's cleanup path.\n\n### Fix\n\nThe first commit skips callbacks that are not set, and documents that they are\noptional. The second discounts the transactions already queued for deletion\ninstead of requiring `mapWallet` to be empty.\n\nThey are kept separate because the second defect masks the first: with only the\nlistener fix applied, the migration surfaces the real error\n`Error: Not all transaction records were migrated (-4)` instead of\n`std::bad_function_call (-1)`.\n\n### Testing\n\n`src/wallet/test/db_tests.cpp` gains a regression test covering a listener with\nonly one callback set, for both commit and abort. It fails on master with\n`std::bad_function_call` and passes with the fix.\n\n`test/functional/wallet_migration.py` gains a case migrating a blank legacy\nwallet with a watch-only address that has received a transaction. The test is\ntaken from #36483.\n\nTo reproduce on master, apply the functional test alone and run\n`wallet_migration.py`.\n\nFixes #36483", "commits": [ { "sha": "72889f7e1e9adaba4a449cbacca72a58e2b36bcf", "date": "2026-10-20T11:32:00Z", "message": "wallet: skip unset db txn listener callbacks\n\nDbTxnListener declares on_commit and on_abort as plain std::function\nmembers and callers may set only the one they need. RemoveTxs() does\nexactly that: it registers a listener with on_commit set and on_abort\nleft empty.\n\nTxnCommit() and TxnAbort() invoked both unconditionally, so aborting a\ndb txn in which RemoveTxs() had run threw std::bad_function_call. The\nexception escaped the wallet, replacing the error that caused the abort\nwith an unhelpful \"std::bad_function_call\" RPC error and skipping the\ncaller's cleanup path.\n\nSkip callbacks that are not set, and document that they are optional." }, { "sha": "50f254e53ac357e5a8315062c634e36071e1aa19", "date": "2026-10-20T11:32:00Z", "message": "wallet: fix migration of watch-only wallets\n\nWhen the wallet being migrated has no spendable material,\nApplyMigrationData() asserts that no records are left behind in it. The\naddress book half of that check works because DelAddressBookWithDB()\nerases from m_address_book straight away. The transaction half cannot:\nRemoveTxs() only erases the records from disk and defers the mapWallet\nremoval to the db txn's on_commit listener, which runs after\nApplyMigrationData() has returned.\n\nmapWallet is therefore never empty at that point, so migrating a\nwatch-only wallet that has transactions always failed with\n\"Error: Not all transaction records were migrated\".\n\nDiscount the transactions queued for deletion instead." } ], "timeline": [ { "t": "2026-10-22T06:47:34Z", "kind": "comment", "who": "Naomi-Gift", "assoc": "NONE", "text": "utACK 50f254e53ac357e5a8315062c634e36071e1aa19", "id": "c:6334608827", "url": "https://github.com/bitcoin/bitcoin/pull/36583#issuecomment-6334608827", "hash": "ce58fb57eb581b67", "edited": null } ], "labels_log": [ { "t": "2026-10-20T12:08:55Z", "action": "labeled", "label": "Wallet", "who": "DrahtBot" } ], "state_log": [], "text_chars": 4125, "text_tokens_estimate": 1031, "changed_paths": [ "src/wallet/test/db_tests.cpp", "src/wallet/wallet.cpp", "src/wallet/walletdb.cpp", "src/wallet/walletdb.h", "test/functional/wallet_migration.py" ], "files": [ { "path": "src/wallet/test/db_tests.cpp", "add": 35, "del": 0 }, { "path": "src/wallet/wallet.cpp", "add": 5, "del": 1 }, { "path": "src/wallet/walletdb.cpp", "add": 2, "del": 2 }, { "path": "src/wallet/walletdb.h", "add": 2, "del": 0 }, { "path": "test/functional/wallet_migration.py", "add": 20, "del": 0 } ], "test_lines": 55, "git": { "head": "50f254e53ac357e5a8315062c634e36071e1aa19", "head_matches_backup": true, "base": "6799119cef7ead71e2b2fc7928a0ea58d720c708", "patch_id": "1c222ae351acf073", "commits": [ { "sha": "72889f7e1e", "subject": "wallet: skip unset db txn listener callbacks", "files": 3, "add": 39, "del": 2 }, { "sha": "50f254e53a", "subject": "wallet: fix migration of watch-only wallets", "files": 2, "add": 25, "del": 1 } ], "patch_truncated": false }, "patch_id": "1c222ae351acf073", "input_hash": "4385c6daa3a6af11", "extracted_at": "2026-11-02T01:09:49+00:00" }