From a154696cbe1d527915fe4eebb61463e1164a059f Mon Sep 17 00:00:00 2001
From: Jason Paulos <jasonpaulos@users.noreply.github.com>
Date: Thu, 1 Apr 2021 15:36:09 -0400
Subject: [PATCH] Fix encoding of all 0 lease and assetMetadataHash

---
 src/transaction.ts     |  26 +++++++----
 tests/5.Transaction.js | 101 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+), 9 deletions(-)

diff --git a/src/transaction.ts b/src/transaction.ts
index 536d64fa2..513bcd8e2 100644
--- a/src/transaction.ts
+++ b/src/transaction.ts
@@ -371,20 +371,24 @@ export class Transaction implements TransactionStorageStructure {
       txn.assetMetadataHash.length !== 0
     ) {
       if (typeof txn.assetMetadataHash === 'string') {
-        const encoded = Buffer.from(txn.assetMetadataHash);
-        if (encoded.byteLength !== ASSET_METADATA_HASH_LENGTH) {
-          throw Error(
-            `assetMetadataHash must be a ${ASSET_METADATA_HASH_LENGTH} byte Uint8Array or string.`
-          );
-        }
-        txn.assetMetadataHash = new Uint8Array(encoded);
-      } else if (
+        txn.assetMetadataHash = new Uint8Array(
+          Buffer.from(txn.assetMetadataHash)
+        );
+      }
+
+      if (
         txn.assetMetadataHash.constructor !== Uint8Array ||
         txn.assetMetadataHash.byteLength !== ASSET_METADATA_HASH_LENGTH
-      )
+      ) {
         throw Error(
           `assetMetadataHash must be a ${ASSET_METADATA_HASH_LENGTH} byte Uint8Array or string.`
         );
+      }
+
+      if (txn.assetMetadataHash.every((value) => value === 0)) {
+        // if hash contains all 0s, omit it
+        txn.assetMetadataHash = undefined;
+      }
     } else {
       txn.assetMetadataHash = undefined;
     }
@@ -401,6 +405,10 @@ export class Transaction implements TransactionStorageStructure {
         throw Error(
           `lease must be of length ${ALGORAND_TRANSACTION_LEASE_LENGTH.toString()}.`
         );
+      if (txn.lease.every((value) => value === 0)) {
+        // if lease contains all 0s, omit it
+        txn.lease = new Uint8Array(0);
+      }
     } else {
       txn.lease = new Uint8Array(0);
     }
diff --git a/tests/5.Transaction.js b/tests/5.Transaction.js
index a4e93ac78..d34febe4c 100644
--- a/tests/5.Transaction.js
+++ b/tests/5.Transaction.js
@@ -145,6 +145,107 @@ describe('Sign', () => {
     );
   });
 
+  it('should not drop a note of all zeros', () => {
+    const txnWithNote = new algosdk.Transaction({
+      from: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      to: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      fee: 10,
+      amount: 847,
+      firstRound: 51,
+      lastRound: 61,
+      genesisHash: 'JgsgCaCTqIaLeVhyL6XlRu3n7Rfk2FxMeK+wRSaQ7dI=',
+      note: new Uint8Array(32),
+    });
+
+    const txnWithoutNote = new algosdk.Transaction({
+      from: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      to: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      fee: 10,
+      amount: 847,
+      firstRound: 51,
+      lastRound: 61,
+      genesisHash: 'JgsgCaCTqIaLeVhyL6XlRu3n7Rfk2FxMeK+wRSaQ7dI=',
+    });
+
+    const serializedWithNote = algosdk.encodeUnsignedTransaction(txnWithNote);
+    const serializedWithoutNote = algosdk.encodeUnsignedTransaction(
+      txnWithoutNote
+    );
+
+    assert.notDeepStrictEqual(serializedWithNote, serializedWithoutNote);
+  });
+
+  it('should drop a lease of all zeros', () => {
+    const txnWithLease = new algosdk.Transaction({
+      from: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      to: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      fee: 10,
+      amount: 847,
+      firstRound: 51,
+      lastRound: 61,
+      genesisHash: 'JgsgCaCTqIaLeVhyL6XlRu3n7Rfk2FxMeK+wRSaQ7dI=',
+      lease: new Uint8Array(32),
+    });
+
+    const txnWithoutLease = new algosdk.Transaction({
+      from: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      to: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',
+      fee: 10,
+      amount: 847,
+      firstRound: 51,
+      lastRound: 61,
+      genesisHash: 'JgsgCaCTqIaLeVhyL6XlRu3n7Rfk2FxMeK+wRSaQ7dI=',
+    });
+
+    const serializedWithLease = algosdk.encodeUnsignedTransaction(txnWithLease);
+    const serializedWithoutLease = algosdk.encodeUnsignedTransaction(
+      txnWithoutLease
+    );
+
+    assert.deepStrictEqual(serializedWithLease, serializedWithoutLease);
+  });
+
+  it('should drop an assetMetadataHash of all zeros', () => {
+    const address =
+      'BH55E5RMBD4GYWXGX5W5PJ5JAHPGM5OXKDQH5DC4O2MGI7NW4H6VOE4CP4';
+
+    const txnWithHash = new algosdk.Transaction({
+      from: address,
+      fee: 10,
+      firstRound: 322575,
+      lastRound: 323575,
+      genesisHash: 'SGO1GKSzyE7IEPItTxCByw9x8FmnrCDexi9/cOUJOiI=',
+      assetIndex: 1234,
+      assetManager: address,
+      assetReserve: address,
+      assetFreeze: address,
+      assetClawback: address,
+      type: 'acfg',
+      assetMetadataHash: new Uint8Array(32),
+    });
+
+    const txnWithoutHash = new algosdk.Transaction({
+      from: address,
+      fee: 10,
+      firstRound: 322575,
+      lastRound: 323575,
+      genesisHash: 'SGO1GKSzyE7IEPItTxCByw9x8FmnrCDexi9/cOUJOiI=',
+      assetIndex: 1234,
+      assetManager: address,
+      assetReserve: address,
+      assetFreeze: address,
+      assetClawback: address,
+      type: 'acfg',
+    });
+
+    const serializedWithHash = algosdk.encodeUnsignedTransaction(txnWithHash);
+    const serializedWithoutHash = algosdk.encodeUnsignedTransaction(
+      txnWithoutHash
+    );
+
+    assert.deepStrictEqual(serializedWithHash, serializedWithoutHash);
+  });
+
   it('should be able to prettyprint and go toString without throwing', () => {
     const o = {
       from: '7ZUECA7HFLZTXENRV24SHLU4AVPUTMTTDUFUBNBD64C73F3UHRTHAIOF6Q',