refactor(core): use errors.Is for sentinel error comparisons in blockchain.go

[gzliudan]

Description

Replace direct == / != comparisons against sentinel errors in core/blockchain.go with errors.Is, matching modern Go idiom (used elsewhere in this file, e.g. errors.Is(err, ErrGenesisAllocUnavailable)).

errors.Is is behaviorally identical for these plain errors.New sentinels today, but also matches wrapped errors (fmt.Errorf("...: %w", err)), so future refactors that wrap these sentinels won't silently break insertion-path error handling.

Changes

11 comparisons updated:

Sentinel	Sites	Functions
consensus.ErrPrunedAncestor	3	insertChain, insertSidechain, getResultBlock
consensus.ErrFutureBlock	2	insertChain
consensus.ErrUnknownAncestor	3	insertChain
ErrKnownBlock	3	insertChain, getResultBlock
ErrStopPreparingBlock	1	getResultBlock — err != ErrStopPreparingBlock → !errors.Is(err, ErrStopPreparingBlock) (negation preserved: only non-stop errors are reported as bad blocks)

Untouched by design: switch err { case ErrKnownBlock: ... } in prepareBlock (switch-case form, case nil branch present).

Testing

• gofmt / goimports clean, go vet ./core/ clean
• make all builds
• go test ./core/... — all pass
• make test — full suite, 0 FAIL
• make tidy / make generate — no changes

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Team

Run ID: 0f47b933-fda7-4e3a-964e-ba6dca4d52f1

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[Copilot]

🟢 Approval recommended

The focused, mechanically consistent changes preserve current behavior while correctly supporting wrapped sentinel errors.

Pull request overview

Modernizes sentinel-error handling in blockchain insertion paths so wrapped errors are recognized correctly.

Changes:

• Replaces direct sentinel comparisons with errors.Is.
• Preserves negation when handling ErrStopPreparingBlock.

File summaries

File	Description
core/blockchain.go	Updates sentinel-error checks in block insertion and processing paths.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.