fix: state migration for layout that included used_aux_parent_blocks#141
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PR #116 removed the unconditional `used_aux_parent_blocks: LookupSet<H256>` field from the contract state without providing a migration. Contracts initialized between #101 (2025-06-06) and #116 (2026-03-18) — e.g. zcash-client.n-bridge.testnet — still carry that field on-chain, so deploying current wasm over them panics on every call with "Cannot deserialize the contract state". Replace the previous migration (pre-`network` layout, already applied to existing deployments) with one that reads the 9-field layout and drops `used_aux_parent_blocks`. `network` is carried over from the old state, so `migrate` no longer takes arguments. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
olga24912
requested changes
Jun 11, 2026
Keep both historical layouts: BtcLightClientV1 (pre-#97, no network) and BtcLightClientV2 (#101..#116, with used_aux_parent_blocks). migrate() detects which variant is stored — borsh requires full buffer consumption, so exactly one layout parses. Already-current state is a no-op, making re-runs safe. The network argument is only required for V1 state. Tests pull the wasm currently deployed on mainnet, init it in a sandbox, upgrade to the locally built wasm and call migrate: - zcash (zcash-client.bridge.near, pre-#116 layout): repair path - bitcoin (btc-client.bridge.near, current layout): no-op path The wasm is fetched via plain RPC because near_workspaces::mainnet() fails to parse responses from current mainnet nodes. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
All btc contracts (mainnet and testnet) were migrated to the current layout in March/April 2026; zcash and litecoin deployments are on the V2 layout. migrate() now takes no arguments. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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olga24912
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Problem
The zcash testnet relayer is down: every call to
zcash-client.n-bridge.testnetpanics withCannot deserialize the contract statesince the 2026-06-10 release deploy.#116 removed the unconditional
used_aux_parent_blocks: LookupSet<H256>field from the contract state struct without adding a migration. Any contract initialized between #101 (2025-06-06) and #116 (2026-03-18) carries that field in its on-chain state, so deploying current wasm over it makes borsh state deserialization fail on every method call.Survey of all deployments:
btc-client.bridge.nearbtc-client-v4.testnetzcash-client.n-bridge.testnetused_aux_parent_blocks) — currently downzcash-client.bridge.nearlitecoin-client.n-bridge.testnetFix
migrate()(no arguments) auto-detects the stored state variant (borsh requires full buffer consumption, so exactly one layout can parse):migrateis safeBtcLightClientV2(Support Dogecoin #101..Extra script_sig checks on Dogecoin Blocks submission #116, hasused_aux_parent_blocks) → drops the field,networkis carried over from stateThe pre-#97 layout (no
networkfield) is not handled: no deployment is on it anymore.Tests
Both tests pull the wasm currently deployed on mainnet, init it in a sandbox, upgrade to the locally built wasm and call
migrate:test_zcash::test_migration_from_mainnet_wasm—zcash-client.bridge.nearwasm (pre-Extra script_sig checks on Dogecoin Blocks submission #116 layout): verifies calls fail before migration with the exact production error, succeed after, and that headers/submissions survive.test_basics::test_migration_from_mainnet_wasm—btc-client.bridge.nearwasm (already current layout): verifies the no-op path keeps state intact.The wasm is fetched via plain JSON-RPC because
near_workspaces::mainnet()(0.20.1) fails to parse responses from current mainnet nodes.Deployment
After merge:
make build-zcash, deploy tozcash-client.n-bridge.testnetwith a batchedmigratecall ({}). The same migration is required forzcash-client.bridge.nearandlitecoin-client.n-bridge.testnetwith their next upgrades.Notes
LookupSetprefix are left orphaned; only Dogecoin deployments ever wrote to it, and none exist. If a Dogecoin contract initialized in the Support Dogecoin #101..Extra script_sig checks on Dogecoin Blocks submission #116 era ever surfaces, it needs more than this:ExtendedHeaderalso lost itsaux_parent_blockfield in Extra script_sig checks on Dogecoin Blocks submission #116, so itsheaders_poolentries have a stale layout too.🤖 Generated with Claude Code