From a60ccded75fae08400b64124622904cc8882e66e Mon Sep 17 00:00:00 2001
From: Andrius Dagys <andrius.dagys@r3.com>
Date: Tue, 1 Aug 2017 11:42:36 +0100
Subject: [PATCH] Minor: Add a test to ensure "identical" issue transactions
 have different ids (#1145)

* Add a test to ensure identical issue transactions have different ids

* Fix a PMT test
---
 .../net/corda/core/contracts/Structures.kt    |  1 +
 .../corda/core/contracts/TransactionTests.kt  | 20 +++++++++++++++++++
 .../core/crypto/PartialMerkleTreeTest.kt      | 17 ++++++++++++----
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/core/src/main/kotlin/net/corda/core/contracts/Structures.kt b/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
index 52e449768c..fc587ab8e8 100644
--- a/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
+++ b/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
@@ -447,6 +447,7 @@ fun JarInputStream.extractFile(path: String, outputTo: OutputStream) {
  */
 @CordaSerializable
 class PrivacySalt(bytes: ByteArray) : OpaqueBytes(bytes) {
+    /** Constructs a salt with a randomly-generated 32 byte value. */
     constructor() : this(secureRandomBytes(32))
 
     init {
diff --git a/core/src/test/kotlin/net/corda/core/contracts/TransactionTests.kt b/core/src/test/kotlin/net/corda/core/contracts/TransactionTests.kt
index b8f31c76eb..984d3b2f91 100644
--- a/core/src/test/kotlin/net/corda/core/contracts/TransactionTests.kt
+++ b/core/src/test/kotlin/net/corda/core/contracts/TransactionTests.kt
@@ -15,6 +15,7 @@ import org.junit.Test
 import java.security.KeyPair
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
+import kotlin.test.assertNotEquals
 
 class TransactionTests : TestDependencyInjectionBase() {
     private fun makeSigned(wtx: WireTransaction, vararg keys: KeyPair, notarySig: Boolean = true): SignedTransaction {
@@ -152,4 +153,23 @@ class TransactionTests : TestDependencyInjectionBase() {
 
         assertFailsWith<TransactionVerificationException.NotaryChangeInWrongTransactionType> { buildTransaction() }
     }
+
+    @Test
+    fun `transactions with identical contents must have different ids`() {
+        val outputState = TransactionState(DummyContract.SingleOwnerState(0, ALICE), DUMMY_NOTARY)
+        fun buildTransaction() = WireTransaction(
+                inputs = emptyList(),
+                attachments = emptyList(),
+                outputs = listOf(outputState),
+                commands = listOf(dummyCommand(DUMMY_KEY_1.public, DUMMY_KEY_2.public)),
+                notary = null,
+                timeWindow = null,
+                privacySalt = PrivacySalt() // Randomly-generated – used for calculating the id
+        )
+
+        val issueTx1 = buildTransaction()
+        val issueTx2 = buildTransaction()
+
+        assertNotEquals(issueTx1.id, issueTx2.id)
+    }
 }
diff --git a/core/src/test/kotlin/net/corda/core/crypto/PartialMerkleTreeTest.kt b/core/src/test/kotlin/net/corda/core/crypto/PartialMerkleTreeTest.kt
index cebc33a218..e4547b9e5a 100644
--- a/core/src/test/kotlin/net/corda/core/crypto/PartialMerkleTreeTest.kt
+++ b/core/src/test/kotlin/net/corda/core/crypto/PartialMerkleTreeTest.kt
@@ -127,8 +127,11 @@ class PartialMerkleTreeTest : TestDependencyInjectionBase() {
 
     @Test
     fun `same transactions with different notaries have different ids`() {
-        val wtx1 = makeSimpleCashWtx(DUMMY_NOTARY)
-        val wtx2 = makeSimpleCashWtx(MEGA_CORP)
+        // We even use the same privacySalt, and thus the only difference between the two transactions is the notary party.
+        val privacySalt = PrivacySalt()
+        val wtx1 = makeSimpleCashWtx(DUMMY_NOTARY, privacySalt)
+        val wtx2 = makeSimpleCashWtx(MEGA_CORP, privacySalt)
+        assertEquals(wtx1.privacySalt, wtx2.privacySalt)
         assertNotEquals(wtx1.id, wtx2.id)
     }
 
@@ -235,14 +238,20 @@ class PartialMerkleTreeTest : TestDependencyInjectionBase() {
         hm1.serialize()
     }
 
-    private fun makeSimpleCashWtx(notary: Party, timeWindow: TimeWindow? = null, attachments: List<SecureHash> = emptyList()): WireTransaction {
+    private fun makeSimpleCashWtx(
+            notary: Party,
+            privacySalt: PrivacySalt = PrivacySalt(),
+            timeWindow: TimeWindow? = null,
+            attachments: List<SecureHash> = emptyList()
+    ): WireTransaction {
         return WireTransaction(
                 inputs = testTx.inputs,
                 attachments = attachments,
                 outputs = testTx.outputs,
                 commands = testTx.commands,
                 notary = notary,
-                timeWindow = timeWindow
+                timeWindow = timeWindow,
+                privacySalt = privacySalt
         )
     }
 }