fix tob audit rounding patterns 1,3

makerdao · Dec 8, 2017 · cb5d024 · cb5d024
1 parent f7b6b45
commit cb5d024
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Showing 3 changed files with 6 additions and 19 deletions.
diff --git a/src/sai.t.sol b/src/sai.t.sol
@@ -1429,22 +1429,6 @@ contract TapTest is SaiTestBase {
 
         tap.bust(51 ether);
     }
-    function testTapBustHealsNetJoy() public {
-        sai.mint(tap, 20 ether);
-        sin.mint(tap, 10 ether);
-
-        tap.bust(0 ether);
-        assertEq(tap.joy(), 10 ether);
-        assertEq(tap.woe(),  0 ether);
-    }
-    function testTapBustHealsNetWoe() public {
-        sai.mint(tap, 10 ether);
-        sin.mint(tap, 20 ether);
-
-        tap.bust(0 ether);
-        assertEq(tap.joy(),  0 ether);
-        assertEq(tap.woe(), 10 ether);
-    }
     function testTapBustFlipHealsNetJoy() public {
         sai.mint(tap, 10 ether);
         sin.mint(tap, 20 ether);

diff --git a/src/tap.sol b/src/tap.sol
@@ -73,15 +73,14 @@ contract SaiTap is DSThing {
         return rmul(wad, wmul(s2s(), gap));
     }
     function flip(uint wad) internal {
+        require(ask(wad) > 0);
         skr.push(msg.sender, wad);
         sai.pull(msg.sender, ask(wad));
         heal();
     }
     function flop(uint wad) internal {
         skr.mint(sub(wad, fog()));
-        skr.push(msg.sender, wad);
-        sai.pull(msg.sender, ask(wad));
-        heal();
+        flip(wad);
         require(joy() == 0);  // can't flop into surplus
     }
     function flap(uint wad) internal {

diff --git a/src/tub.sol b/src/tub.sol
@@ -174,6 +174,7 @@ contract SaiTub is DSThing, SaiTubEvents {
     }
     function join(uint wad) public note {
         require(!off);
+        require(ask(wad) > 0);
         require(gem.transferFrom(msg.sender, this, ask(wad)));
         skr.mint(msg.sender, wad);
     }
@@ -262,9 +263,11 @@ contract SaiTub is DSThing, SaiTubEvents {
     function draw(bytes32 cup, uint wad) public note {
         require(!off);
         require(msg.sender == cups[cup].lad);
+        require(rdiv(wad, chi()) > 0);
 
         cups[cup].art = add(cups[cup].art, rdiv(wad, chi()));
         rum = add(rum, rdiv(wad, chi()));
+
         cups[cup].ire = add(cups[cup].ire, rdiv(wad, rhi()));
         sai.mint(cups[cup].lad, wad);
 
@@ -278,6 +281,7 @@ contract SaiTub is DSThing, SaiTubEvents {
 
         cups[cup].art = sub(cups[cup].art, rdiv(wad, chi()));
         rum = sub(rum, rdiv(wad, chi()));
+
         cups[cup].ire = sub(cups[cup].ire, rdiv(add(wad, owe), rhi()));
         sai.burn(msg.sender, wad);