From 1bd928750958586c76a6a1812a3931f9d2448c88 Mon Sep 17 00:00:00 2001
From: Dickson <dickson.wu654@gmail.com>
Date: Tue, 1 Sep 2026 02:04:43 +0000
Subject: [PATCH] fix(cheatcodes): preserve non-empty zero bytecode

---
 src/kontrol/kdist/cheatcodes.md                   |  2 +-
 src/tests/integration/test-data/foundry-prove-all |  1 +
 .../foundry/test/AccountParamsTest.t.sol          | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/kontrol/kdist/cheatcodes.md b/src/kontrol/kdist/cheatcodes.md
index dfbc0f190..c9f66578d 100644
--- a/src/kontrol/kdist/cheatcodes.md
+++ b/src/kontrol/kdist/cheatcodes.md
@@ -1392,7 +1392,7 @@ We don't care about the values because they will be processed in the `custom_ste
     rule <k> #setCode ACCTID CODE => .K ... </k>
          <account>
            <acctID> ACCTID </acctID>
-           <code> _ => #if #asWord(CODE) ==Int 0 #then .Bytes #else CODE #fi </code>
+           <code> _ => #if lengthBytes(CODE) ==Int 0 #then .Bytes #else CODE #fi </code>
            ...
          </account>
 ```
diff --git a/src/tests/integration/test-data/foundry-prove-all b/src/tests/integration/test-data/foundry-prove-all
index c37ddfc25..d845183be 100644
--- a/src/tests/integration/test-data/foundry-prove-all
+++ b/src/tests/integration/test-data/foundry-prove-all
@@ -1,6 +1,7 @@
 AccountParamsTest.testDealConcrete()
 AccountParamsTest.testDealSymbolic(uint256)
 AccountParamsTest.testEtchConcrete()
+AccountParamsTest.testEtchEmptyAndZero()
 AccountParamsTest.testEtchSymbolic(bytes)
 AccountParamsTest.testFail_GetNonce_false()
 AccountParamsTest.testFail_GetNonce_true()
diff --git a/src/tests/integration/test-data/foundry/test/AccountParamsTest.t.sol b/src/tests/integration/test-data/foundry/test/AccountParamsTest.t.sol
index 1f1a39931..f8af49be8 100644
--- a/src/tests/integration/test-data/foundry/test/AccountParamsTest.t.sol
+++ b/src/tests/integration/test-data/foundry/test/AccountParamsTest.t.sol
@@ -21,6 +21,21 @@ contract AccountParamsTest is Test {
         assertEq(address(124).code, code);
     }
 
+    function testEtchEmptyAndZero() public {
+        address emptyAddress = address(124);
+        address zeroAddress = address(125);
+        bytes memory emptyCode = bytes("");
+        bytes memory zeroCode = hex"00";
+
+        vm.etch(emptyAddress, emptyCode);
+        vm.etch(zeroAddress, zeroCode);
+
+        assertEq(emptyAddress.code, emptyCode);
+        assertEq(emptyAddress.code.length, 0);
+        assertEq(zeroAddress.code, zeroCode);
+        assertEq(zeroAddress.code.length, 1);
+    }
+
     function testEtchSymbolic(bytes calldata code) public {
         vm.etch(address(124), code);
         assertEq(address(124).code, code);