From fa3ba105be60dcd0603e34c1eb85b7da28a9f047 Mon Sep 17 00:00:00 2001
From: Josselin <josselin@trailofbits.com>
Date: Fri, 3 Apr 2020 17:18:15 +0200
Subject: [PATCH] Add psender Improve properties

---
 slither/tools/properties/platforms/echidna.py                 | 1 +
 .../properties/properties/ercs/erc20/properties/transfer.py   | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/slither/tools/properties/platforms/echidna.py b/slither/tools/properties/platforms/echidna.py
index 052c6d8b5..f02783429 100644
--- a/slither/tools/properties/platforms/echidna.py
+++ b/slither/tools/properties/platforms/echidna.py
@@ -14,6 +14,7 @@ def generate_echidna_config(output_dir: Path, addresses: Addresses) -> str:
     content = 'prefix: crytic_\n'
     content += f'deployer: "{addresses.owner}"\n'
     content += f'sender: ["{addresses.user}", "{addresses.attacker}"]\n'
+    content += f'psender: "{addresses.user}"\n'
     content += 'coverage: true\n'
     filename = 'echidna_config.yaml'
     write_file(output_dir, filename, content)
diff --git a/slither/tools/properties/properties/ercs/erc20/properties/transfer.py b/slither/tools/properties/properties/ercs/erc20/properties/transfer.py
index 922f0e0fb..02860e4ab 100644
--- a/slither/tools/properties/properties/ercs/erc20/properties/transfer.py
+++ b/slither/tools/properties/properties/ercs/erc20/properties/transfer.py
@@ -64,6 +64,10 @@ ERC20_Transferable = [
              description='No one should be able to send tokens to the address 0x0 (transferFrom).',
              content='''
 \t\tuint balance = this.balanceOf(msg.sender);
+\t\tif (balance == 0){
+\t\t\trevert();
+\t\t}
+\t\tapprove(msg.sender, balance);
 \t\treturn transferFrom(msg.sender, address(0x0), this.balanceOf(msg.sender));''',
              type=PropertyType.CODE_QUALITY,
              return_type=PropertyReturn.FAIL_OR_THROW,