fix _SolveQuadraticFunctionForTrade sub error

2021-01-15 22:45:33 +08:00
parent 70c0df01d5
commit 211b5e0172
1 changed files with 8 additions and 3 deletions
--- a/contracts/lib/DODOMath.sol
+++ b/contracts/lib/DODOMath.sol
@@ -165,10 +165,10 @@ library DODOMath {

        bool bSig;
        if (bAbs >= part2) {
-            bAbs = bAbs.sub(part2);
+            bAbs = bAbs - part2;
            bSig = false;
        } else {
-            bAbs = part2.sub(bAbs);
+            bAbs = part2 - bAbs;
            bSig = true;
        }
        bAbs = bAbs.div(DecimalMath.ONE);
@@ -190,6 +190,11 @@ library DODOMath {
            numerator = bAbs.add(squareRoot);
        }

-        return V1.sub(DecimalMath.divCeil(numerator, denominator));
+        uint256 V2 = DecimalMath.divCeil(numerator, denominator);
+        if (V2 > V1) {
+            return 0;
+        } else {
+            return V1 - V2;
+        }
    }
 }