Cleanup related to #296

- rewrote comment
- added "found" booleans to getter methods to clarify logic

x/ccv/provider/keeper/keeper.go

@@ -565,13 +565,13 @@ func (k Keeper) SetValsetUpdateBlockHeight(ctx sdk.Context, valsetUpdateId, bloc
 }
 
 // GetValsetUpdateBlockHeight gets the block height for a given valset update id
-func (k Keeper) GetValsetUpdateBlockHeight(ctx sdk.Context, valsetUpdateId uint64) uint64 {
+func (k Keeper) GetValsetUpdateBlockHeight(ctx sdk.Context, valsetUpdateId uint64) (uint64, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.ValsetUpdateBlockHeightKey(valsetUpdateId))
 	if bz == nil {
-		return 0
+		return 0, false
 	}
-	return binary.BigEndian.Uint64(bz)
+	return binary.BigEndian.Uint64(bz), true
 }
 
 // DeleteValsetUpdateBlockHeight deletes the block height value for a given vaset update id
@@ -661,14 +661,14 @@ func (k Keeper) SetInitChainHeight(ctx sdk.Context, chainID string, height uint6
 }
 
 // GetInitChainHeight returns the provider block height when the given consumer chain was initiated
-func (k Keeper) GetInitChainHeight(ctx sdk.Context, chainID string) uint64 {
+func (k Keeper) GetInitChainHeight(ctx sdk.Context, chainID string) (uint64, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.InitChainHeightKey(chainID))
 	if bz == nil {
-		return 0
+		return 0, false
 	}
 
-	return binary.BigEndian.Uint64(bz)
+	return binary.BigEndian.Uint64(bz), true
 }
 
 // DeleteInitChainHeight deletes the block height value for which the given consumer chain's channel was established

x/ccv/provider/keeper/relay.go

@@ -205,14 +205,15 @@ func (k Keeper) OnRecvSlashPacket(ctx sdk.Context, packet channeltypes.Packet, d
 func (k Keeper) HandleSlashPacket(ctx sdk.Context, chainID string, data ccv.SlashPacketData) (success bool, err error) {
 	// map VSC ID to infraction height for the given chain ID
 	var infractionHeight uint64
+	var found bool
 	if data.ValsetUpdateId == 0 {
-		infractionHeight = k.GetInitChainHeight(ctx, chainID)
+		infractionHeight, found = k.GetInitChainHeight(ctx, chainID)
 	} else {
-		infractionHeight = k.GetValsetUpdateBlockHeight(ctx, data.ValsetUpdateId)
+		infractionHeight, found = k.GetValsetUpdateBlockHeight(ctx, data.ValsetUpdateId)
 	}
 
-	// return if there isn't any initial chain height for the consumer chain
-	if infractionHeight == 0 {
+	// return error if we cannot find infraction height matching the validator update id
+	if !found {
 		return false, fmt.Errorf("cannot find infraction height matching the validator update id %d for chain %s", data.ValsetUpdateId, chainID)
 	}