CancelUndelegate in staking module

[jasonsprouse]

I have undelegated on accident a couple times when I meant to delegate to a validator. I heard another dev say this is a feature that they would like to have - canceling an undelegate staking action, but no one has gotten around to implementing it.

The question I have for implementation is around the state change when delegate and undelegate occurs.

Delegate adds the sdk.Coins to the staking module.

cosmos-sdk/x/staking/keeper/delegation.go

Lines 603 to 606 in 1581289

	coins := sdk.NewCoins(sdk.NewCoin(k.BondDenom(ctx), bondAmt))
	if err := k.bankKeeper.DelegateCoinsFromAccountToModule(ctx, delegatorAddress, sendName, coins); err != nil {
	return sdk.Dec{}, err
	}

Undelegate sends the bonded tokens to a not bonded pool as seen:

Here:

cosmos-sdk/x/staking/keeper/delegation.go

Lines 756 to 763 in 1581289

	// transfer the validator tokens to the not bonded pool
	if validator.IsBonded() {
	k.bondedTokensToNotBonded(ctx, returnAmount)
	}
	completionTime := ctx.BlockHeader().Time.Add(k.UnbondingTime(ctx))
	ubd := k.SetUnbondingDelegationEntry(ctx, delAddr, valAddr, ctx.BlockHeight(), completionTime, returnAmount)
	k.InsertUBDQueue(ctx, ubd, completionTime)

and Here:

cosmos-sdk/x/staking/keeper/pool.go

Line 22 in 1581289

if err := k.bankKeeper.SendCoinsFromModuleToModule(ctx, types.BondedPoolName, types.NotBondedPoolName, coins); err != nil {

There is also a state change to start the que for the unbonding period.

cosmos-sdk/x/staking/keeper/delegation.go

Line 763 in 1581289

k.InsertUBDQueue(ctx, ubd, completionTime)

If we are to restore - or cancel, this undelegate transaction. All of these conditions would need to be addressed.

Is this a functionality that others want?

[jasonsprouse]

Pull request that is a WIP - #11025