Fix statemanager empty code bug

packages/statemanager/src/stateManager.ts

@@ -356,9 +356,6 @@ export class DefaultStateManager implements EVMStateManagerInterface {
   async putContractCode(address: Address, value: Uint8Array): Promise<void> {
     this._codeCache?.put(address, value)
     const codeHash = this.keccakFunction(value)
-    if (equalsBytes(codeHash, KECCAK256_NULL)) {
-      return
-    }
 
     if (this.DEBUG) {
       this._debug(`Update codeHash (-> ${short(codeHash)}) for account ${address}`)

packages/statemanager/test/stateManager.code.spec.ts

@@ -148,5 +148,15 @@ describe('StateManager -> Code', () => {
         assert.ok(true, 'successfully threw')
       }
     })
+
+    it('putContractCode with empty code on existing address should correctly propagate', async () => {
+      const stateManager = new DefaultStateManager()
+      const address = Address.zero()
+      await stateManager.putContractCode(address, new Uint8Array([1]))
+      await stateManager.putContractCode(address, new Uint8Array())
+      const account = await stateManager.getAccount(address)
+      assert.ok(account !== undefined)
+      assert.ok(account?.isEmpty())
+    })
   }
 })

packages/vm/src/runTx.ts

@@ -680,10 +680,6 @@ async function _runTx(this: VM, opts: RunTxOpts): Promise<RunTxResult> {
   for (const str of writtenAddresses) {
     const address = Address.fromString(str)
     await this.stateManager.putContractCode(address, new Uint8Array())
-    // TODO verify if this is necessary
-    // `putContractCode` will not `modifyAccountFields` if one tries to put empty code
-    // So explicitly add this here - does this have side effects?
-    await this.stateManager.modifyAccountFields(address, { codeHash: KECCAK256_NULL })
   }
 
   if (enableProfiler) {