From 405de7984241eeafe00441272ca629039e5f992e Mon Sep 17 00:00:00 2001
From: Louis <107303182+0x0Louis@users.noreply.github.com>
Date: Fri, 3 Nov 2023 18:37:35 +0100
Subject: [PATCH] Fix BMCJ div by zero error (#121)

* fix bmcj div by zero

* Fix code style issues with Prettier

---------

Co-authored-by: Lint Action <lint-action@samuelmeuli.com>
---
 contracts/BoostedMasterChefJoe.sol | 20 ++++++++++++---
 test/foundry/UpgradeBMCJ.t.sol     | 41 ++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 4 deletions(-)
 create mode 100644 test/foundry/UpgradeBMCJ.t.sol

diff --git a/contracts/BoostedMasterChefJoe.sol b/contracts/BoostedMasterChefJoe.sol
index 36517a10..6bb25299 100644
--- a/contracts/BoostedMasterChefJoe.sol
+++ b/contracts/BoostedMasterChefJoe.sol
@@ -364,12 +364,15 @@ contract BoostedMasterChefJoe is Initializable, OwnableUpgradeable, ReentrancyGu
     /// @notice Calculates and returns the `amount` of JOE per second
     /// @return amount The amount of JOE emitted per second
     function joePerSec() public view returns (uint256 amount) {
+        uint256 mcv2TotalAllocPoint = MASTER_CHEF_V2.totalAllocPoint();
+        if (mcv2TotalAllocPoint == 0) return 0;
+
         uint256 total = 1000;
         uint256 lpPercent = total.sub(MASTER_CHEF_V2.devPercent()).sub(MASTER_CHEF_V2.treasuryPercent()).sub(
             MASTER_CHEF_V2.investorPercent()
         );
         uint256 lpShare = MASTER_CHEF_V2.joePerSec().mul(lpPercent).div(total);
-        amount = lpShare.mul(MASTER_CHEF_V2.poolInfo(MASTER_PID).allocPoint).div(MASTER_CHEF_V2.totalAllocPoint());
+        amount = lpShare.mul(MASTER_CHEF_V2.poolInfo(MASTER_PID).allocPoint).div(mcv2TotalAllocPoint);
     }
 
     /// @notice View function to see pending JOE on frontend
@@ -396,7 +399,12 @@ contract BoostedMasterChefJoe is Initializable, OwnableUpgradeable, ReentrancyGu
 
         if (block.timestamp > pool.lastRewardTimestamp && pool.totalLpSupply != 0 && pool.allocPoint != 0) {
             uint256 secondsElapsed = block.timestamp - pool.lastRewardTimestamp;
-            uint256 joeReward = secondsElapsed.mul(joePerSec()).mul(pool.allocPoint).div(totalAllocPoint);
+
+            uint256 totalAllocPoint_ = totalAllocPoint;
+            uint256 joeReward = totalAllocPoint_ > 0
+                ? secondsElapsed.mul(joePerSec()).mul(pool.allocPoint).div(totalAllocPoint_)
+                : 0;
+
             accJoePerShare = accJoePerShare.add(
                 joeReward.mul(ACC_TOKEN_PRECISION).mul(10_000 - pool.veJoeShareBp).div(pool.totalLpSupply.mul(10_000))
             );
@@ -449,7 +457,11 @@ contract BoostedMasterChefJoe is Initializable, OwnableUpgradeable, ReentrancyGu
                 uint256 veJoeShareBp = pool.veJoeShareBp;
                 uint256 totalFactor = pool.totalFactor;
 
-                uint256 joeReward = secondsElapsed.mul(joePerSec()).mul(allocPoint).div(totalAllocPoint);
+                uint256 totalAllocPoint_ = totalAllocPoint;
+                uint256 joeReward = totalAllocPoint_ > 0
+                    ? secondsElapsed.mul(joePerSec()).mul(allocPoint).div(totalAllocPoint_)
+                    : 0;
+
                 pool.accJoePerShare = pool.accJoePerShare.add(
                     joeReward.mul(ACC_TOKEN_PRECISION).mul(10_000 - veJoeShareBp).div(lpSupply.mul(10_000))
                 );
@@ -473,7 +485,7 @@ contract BoostedMasterChefJoe is Initializable, OwnableUpgradeable, ReentrancyGu
 
     /// @notice Harvests JOE from `MASTER_CHEF_V2` MCJV2 and pool `MASTER_PID` to this BMCJ contract
     function harvestFromMasterChef() public {
-        MASTER_CHEF_V2.deposit(MASTER_PID, 0);
+        // MASTER_CHEF_V2.deposit(MASTER_PID, 0);
     }
 
     /// @notice Return an user's factor
diff --git a/test/foundry/UpgradeBMCJ.t.sol b/test/foundry/UpgradeBMCJ.t.sol
new file mode 100644
index 00000000..5d70a33d
--- /dev/null
+++ b/test/foundry/UpgradeBMCJ.t.sol
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: MIT
+pragma experimental ABIEncoderV2;
+pragma solidity 0.6.12;
+
+import "forge-std/Test.sol";
+
+import "@openzeppelin/contracts/proxy/ProxyAdmin.sol";
+import "@openzeppelin/contracts/proxy/TransparentUpgradeableProxy.sol";
+
+import "../../contracts/BoostedMasterChefJoe.sol";
+
+contract TestUpgradeBMCJ is Test {
+    ProxyAdmin proxyAdmin = ProxyAdmin(0x246ABeC8f8a542E892934232DB3Fd97A61E3193c);
+    BoostedMasterChefJoe proxy = BoostedMasterChefJoe(0x4483f0b6e2F5486D06958C20f8C39A7aBe87bf8F);
+
+    address ms = 0x2fbB61a10B96254900C03F1644E9e1d2f5E76DD2;
+
+    function setUp() public {
+        vm.createSelectFork(vm.rpcUrl("avalanche"), 37289196);
+    }
+
+    function test_Upgrade() public {
+        uint256 previousTotalAllocPoint = proxy.totalAllocPoint();
+
+        vm.expectRevert("SafeMath: division by zero");
+        proxy.massUpdatePools();
+
+        vm.expectRevert("SafeMath: division by zero");
+        proxy.joePerSec();
+
+        address newImpl = address(new BoostedMasterChefJoe());
+
+        vm.prank(ms);
+        proxyAdmin.upgrade(TransparentUpgradeableProxy(payable(address(proxy))), newImpl);
+
+        assertEq(proxy.joePerSec(), 0);
+        assertEq(proxy.totalAllocPoint(), previousTotalAllocPoint);
+
+        proxy.massUpdatePools();
+    }
+}