fix(evm): remove unnecessary EIP-7825 tx gas limit cap override

[panos-xyz]

Summary

• Remove manual tx_gas_limit_cap = Some(header.gas_limit()) override from MorphEvmConfig
• The override was a workaround for a now-fixed bug where all MorphHardfork variants incorrectly mapped to SpecId::OSAKA

Background

The override was added in commit 508ac07 when the hardfork-to-SpecId mapping was:

Bernoulli/Curie/Morph203/Viridian/Emerald/MPTFork → OSAKA (all OSAKA!)

This caused revm to enforce the EIP-7825 tx gas limit cap (2^24 = 16,777,216) on all blocks, even pre-Osaka ones. Block 16,102,224 contains a transaction (0x600e751e...bad7aa6) with gas_limit = 20,001,453 that was valid under CANCUN spec but rejected by the incorrect OSAKA cap.

The mapping has since been corrected to:

Bernoulli/Curie/Morph203 → CANCUN
Viridian → PRAGUE
Emerald/Jade → OSAKA

With the correct mapping, revm's default tx_gas_limit_cap() handles this properly:

• Pre-OSAKA: u64::MAX (no cap)
• OSAKA+: eip7825::TX_GAS_LIMIT_CAP

The manual override is no longer needed.

Test plan

• cargo check -p morph-evm passes
• cargo test -p morph-evm — 26 tests pass
• Verify node can sync past block 16,102,224 without the override

Summary by CodeRabbit

• Refactor
  • Removed unused gas limit cap configuration code and associated tests.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e8a6f7cf-02ce-4ecf-9816-f2957b96e7df

📥 Commits

Reviewing files that changed from the base of the PR and between 42d7ede and b1a7aae.

📒 Files selected for processing (1)

• crates/evm/src/config.rs

💤 Files with no reviewable changes (1)

• crates/evm/src/config.rs

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📝 Walkthrough

Walkthrough

Configuration cleanup removing tx_gas_limit_cap assignments from EVM environment setup in both the main and next environment contexts, along with the corresponding validation test.

Changes

Cohort / File(s)	Summary
Gas Limit Cap Configuration Removal crates/evm/src/config.rs	Removed cfg_env.tx_gas_limit_cap assignments from evm_env and next_evm_env blocks, including explanatory comments. Deleted unit test test_evm_env_tx_gas_limit_cap_matches_header that validated the cap matched the header gas limit.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• chengwenxi
• anylots

Poem

🐰 The gas cap slips away like morning dew,
No more limits binding what we do,
The test bids farewell, its job now through,
Simpler configs, fresher and new! ✨

🚥 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 directly summarizes the main change: removing an unnecessary EIP-7825 tx gas limit cap override. It's concise, specific, and clearly reflects the primary objective of the pull request.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch worktree-fix+remove-eip7825-override

Warning

Review ran into problems

🔥 Problems

Timed out fetching pipeline failures after 30000ms

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