fix incorrect vesting remainder behavior

also checks vesting schedule range when calculating

x/colinearcore/keeper/msg_server_claim_funds.go

@@ -2,7 +2,6 @@ package keeper
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"math/big"
 	"time"
@@ -53,7 +52,10 @@ func (k msgServer) ClaimFunds(goCtx context.Context, msg *types.MsgClaimFunds) (
 	now := ctx.BlockTime()
 	subAmt, err := colinearmath.CalcAmountVestableLinear(total, remaining, now, leaseBegin, leaseEnd)
 	if err != nil {
-		return nil, errors.New("unable to calculate vestable amount")
+		return nil, fmt.Errorf("unable to calculate vestable amount: %s", err)
+	}
+	if subAmt.Cmp(big.NewInt(0)) == 0 {
+		return nil, fmt.Errorf("no claimable %s (calculated vesting amount is 0)", auction.Denom)
 	}
 
 	// pay from module to user account
@@ -65,7 +67,7 @@ func (k msgServer) ClaimFunds(goCtx context.Context, msg *types.MsgClaimFunds) (
 	// subtract paid amount off of remaining payout tally & commit to chain state
 	newRemaining := new(big.Int)
 	newRemaining.Sub(remaining, subAmt)
-	auction.Remaining = subAmt.String()
+	auction.Remaining = newRemaining.String()
 	k.Keeper.SetAuction(ctx, auction)
 
 	return &types.MsgClaimFundsResponse{}, nil

x/colinearcore/math/vesting.go

@@ -1,6 +1,7 @@
 package colinearmath
 
 import (
+	"fmt"
 	"math/big"
 	"time"
 )
@@ -11,11 +12,15 @@ import (
 func CalcAmountVestableLinear(
 	total *big.Int,
 	remaining *big.Int,
-	date time.Time,
+	now time.Time,
 	beginDate time.Time,
 	endDate time.Time,
 ) (*big.Int, error) {
-	timePassed := big.NewInt(date.Unix() - beginDate.Unix())
+	timePassed := big.NewInt(now.Unix() - beginDate.Unix())
+	if timePassed.Cmp(big.NewInt(0)) == -1 {
+		return nil, fmt.Errorf("time %d is out of range (%d, %d)", now.Unix(), beginDate.Unix(), endDate.Unix())
+	}
+
 	totalTime := big.NewInt(endDate.Unix() - beginDate.Unix())
 
 	taken := big.NewInt(0)