fix: TotalLiquidShares nil handling logic in slashing

Also, both TotalLiquidShares and TotalValidatorBondShares shouldn't be nil in state, this will be handled by a migration later,
for now to avoid crashes it's done in the EndBlocker.

x/lsnative/staking/abci.go

@@ -23,5 +23,26 @@ func BeginBlocker(ctx sdk.Context, k keeper.Keeper) {
 func EndBlocker(ctx sdk.Context, k keeper.Keeper) []abci.ValidatorUpdate {
 	defer telemetry.ModuleMeasureSince(types.ModuleName, time.Now(), telemetry.MetricKeyEndBlocker)
 
+	// FIXME(max): remove this block after state migration is final
+	if ctx.BlockHeight() > 11060956 {
+		validators := k.GetLastValidators(ctx)
+		for _, val := range validators {
+			var valNeedsUpdate bool
+
+			if val.TotalLiquidShares.IsNil() {
+				val.TotalLiquidShares = sdk.ZeroDec()
+				valNeedsUpdate = true
+			}
+			if val.TotalValidatorBondShares.IsNil() {
+				val.TotalValidatorBondShares = sdk.ZeroDec()
+				valNeedsUpdate = true
+			}
+
+			if valNeedsUpdate {
+				k.SetValidator(ctx, val)
+			}
+		}
+	}
+
 	return k.BlockValidatorUpdates(ctx)
 }

x/lsnative/staking/keeper/slash.go

@@ -131,7 +131,12 @@ func (k Keeper) Slash(ctx sdk.Context, consAddr sdk.ConsAddress, infractionHeigh
 	validator = k.RemoveValidatorTokens(ctx, validator, tokensToBurn)
 
 	// Proportionally deduct any liquid tokens from the global total
-	validatorLiquidRatio := validator.TotalLiquidShares.Quo(validator.DelegatorShares)
+	var validatorLiquidRatio sdk.Dec
+	if validator.TotalLiquidShares.IsNil() {
+		validatorLiquidRatio = sdk.ZeroDec()
+	} else {
+		validatorLiquidRatio = validator.TotalLiquidShares.Quo(validator.DelegatorShares)
+	}
 	slashedLiquidTokens := validatorLiquidRatio.Mul(sdk.NewDecFromInt(slashAmount)).TruncateInt()
 	k.DecreaseTotalLiquidStakedTokens(ctx, slashedLiquidTokens)