Update reporter delegated amount during slashing

[pahor167]

Description

Enhance LockedGold contract to update delegated amounts for reporter when slashed and receiving rewards. Add unit tests to verify correct behavior for both reporter and account delegation scenarios.

Tested

Unit tests

---

Note

Update LockedGold.slash to recalculate reporter’s delegated amount when reward is granted and add unit tests covering reporter/account delegation updates.

• Contracts:
  • contracts/governance/LockedGold.sol:
    • In slash, after balance adjustments, also call _updateDelegatedAmount(reporter) to refresh reporter delegation state.
• Tests:
  • test-sol/unit/governance/voting/LockedGold.t.sol:
    • Add tests ensuring reporter’s delegated amount and delegatee voting power update when reporter is delegating and receives reward.
    • Add tests validating both slashed account and reporter delegations are updated when both are delegating.

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[Mc01]

When slashing through GovernanceSlasher the reporter is 0x0 so I would add this exclusion:

Suggested change

	_updateDelegatedAmount(reporter);
	if (reporter != address(0)) {
	_updateDelegatedAmount(reporter);
	}

and appropriate test case for it in LockedGold.t.sol

[Mc01]

Additionally 👉 how about the found issue within unlock function?

function unlock(uint256 value) external nonReentrant {
  ...
  _decrementNonvotingAccountBalance(msg.sender, value);
  _updateDelegatedAmount(msg.sender); // fix for storage
  ...
}

[m-chrzan]

When slashing through GovernanceSlasher the reporter is 0x0 so I would add this exclusion

Yes, this is probably even necessary, otherwise the call to voteSignerToAccount inside _updateDelegatedAmount would revert, making Governance slashings impossible.

[m-chrzan]

Just noting: if I remember correctly, the point of having an updateDelegatedAmount function was that we'd allow the stored delegated amount to diverge from the expected amount (in particular, when the delegator accrues epoch rewards). So this change isn't strictly necessary, more of a convenience that adds gas costs to the slash function.

In fact, even the above call with _updateDelegatedAmount(account) isn't really necessary - since the only slashable actors are validators and validator groups, and those are not allowed to delegate.

[m-chrzan]

When slashing through GovernanceSlasher the reporter is 0x0 so I would add this exclusion

Yes, this is probably even necessary, otherwise the call to voteSignerToAccount inside _updateDelegatedAmount would revert, making Governance slashings impossible.