`BlockNumberToTimestamp` duplication and inconsistencies

[lucasmt]

chain_container.go includes two functions called BlockNumberToTimestamp and blockNumberToTimestamp:

_audits_Ethereum-optimism_optimism_interopv2/op-supernode/supernode/chain_container/chain_container.go

Lines 296 to 301 in be00aaa

	func (c *simpleChainContainer) BlockNumberToTimestamp(ctx context.Context, blocknum uint64) (uint64, error) {
	if c.vncfg == nil {
	return 0, fmt.Errorf("rollup config not available")
	}
	return c.vncfg.Rollup.Genesis.L2Time + (blocknum * c.vncfg.Rollup.BlockTime), nil
	}

_audits_Ethereum-optimism_optimism_interopv2/op-supernode/supernode/chain_container/chain_container.go

Lines 547 to 553 in be00aaa

	// blockNumberToTimestamp converts a block number to its timestamp using rollup config.
	func (c *simpleChainContainer) blockNumberToTimestamp(blockNum uint64) uint64 {
	if c.vncfg == nil {
	return 0
	}
	return c.vncfg.Rollup.Genesis.L2Time + (blockNum * c.vncfg.Rollup.BlockTime)
	}

• These functions are a duplication of each other, except that blockNumberToTimestamp doesn't return an error and just returns 0 if the virtual node config is empty.
• Their calculation seems to assume that the genesis block timestamp is always 0. This is inconsistent with c.vncfg.Rollup.TargetBlockNumber(), which subtracts cfg.Genesis.L2Time to calculate the result.

Status

Fixed in PR #19542.