From a2e35fabce58e5ec100ceb319ae1c82cacc87074 Mon Sep 17 00:00:00 2001
From: Andrew Kozlik <andrew.kozlik@gmail.com>
Date: Wed, 25 Nov 2020 20:41:32 +0100
Subject: [PATCH] chore(legacy): Rename variables in signing to match the names
 in core.

---
 legacy/firmware/signing.c | 42 ++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/legacy/firmware/signing.c b/legacy/firmware/signing.c
index f016a921a9..698c8cf64a 100644
--- a/legacy/firmware/signing.c
+++ b/legacy/firmware/signing.c
@@ -70,7 +70,7 @@ static uint8_t hash_prevouts[32], hash_sequence[32], hash_outputs[32];
 static uint8_t decred_hash_prefix[32];
 #endif
 static uint8_t hash_inputs_check[32];
-static uint64_t to_spend, spending, change_spend;
+static uint64_t total_in, total_out, change_out;
 static uint32_t version = 1;
 static uint32_t lock_time = 0;
 static uint32_t expiry = 0;
@@ -234,6 +234,16 @@ foreach I (idx1): // input to sign                            STAGE_REQUEST_DECR
 clang-format on
 */
 
+static bool add_amount(uint64_t *dest, uint64_t amount) {
+  if (*dest + amount < *dest) {
+    fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow"));
+    signing_abort();
+    return false;
+  }
+  *dest += amount;
+  return true;
+}
+
 void send_req_1_input(void) {
   signing_stage = STAGE_REQUEST_1_INPUT;
   resp.has_request_type = true;
@@ -578,9 +588,9 @@ void signing_init(const SignTx *msg, const CoinInfo *_coin,
 
   signatures = 0;
   idx1 = 0;
-  to_spend = 0;
-  spending = 0;
-  change_spend = 0;
+  total_in = 0;
+  total_out = 0;
+  change_out = 0;
   change_count = 0;
   memzero(&input, sizeof(TxInputType));
   memzero(&resp, sizeof(TxRequest));
@@ -901,12 +911,9 @@ static bool signing_check_output(TxOutputType *txoutput) {
   }
 
   if (is_change) {
-    if (change_spend + txoutput->amount < change_spend) {
-      fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow"));
-      signing_abort();
+    if (!add_amount(&change_out, txoutput->amount)) {
       return false;
     }
-    change_spend += txoutput->amount;
 
     change_count++;
     if (change_count <= 0) {
@@ -916,12 +923,10 @@ static bool signing_check_output(TxOutputType *txoutput) {
     }
   }
 
-  if (spending + txoutput->amount < spending) {
-    fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow"));
-    signing_abort();
+  if (!add_amount(&total_out, txoutput->amount)) {
     return false;
   }
-  spending += txoutput->amount;
+
   int co = compile_output(coin, &root, txoutput, &bin_output, !is_change);
   if (!is_change) {
     layoutProgress(_("Signing transaction"), progress);
@@ -958,7 +963,7 @@ static bool signing_confirm_tx(void) {
     // bypass check for negative fee coins, required for reward TX
   } else {
     // check fees
-    if (spending > to_spend) {
+    if (total_out > total_in) {
       fsm_sendFailure(FailureType_Failure_NotEnoughFunds,
                       _("Not enough funds"));
       signing_abort();
@@ -967,8 +972,8 @@ static bool signing_confirm_tx(void) {
   }
 
   uint64_t fee = 0;
-  if (spending <= to_spend) {
-    fee = to_spend - spending;
+  if (total_out <= total_in) {
+    fee = total_in - total_out;
     if (fee > ((uint64_t)tx_weight * coin->maxfee_kb) / 4000) {
       layoutFeeOverThreshold(coin, fee);
       if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold,
@@ -1002,7 +1007,7 @@ static bool signing_confirm_tx(void) {
   }
 
   // last confirmation
-  layoutConfirmTx(coin, to_spend - change_spend, fee);
+  layoutConfirmTx(coin, total_in - change_out, fee);
   if (!protectButton(ButtonRequestType_ButtonRequest_SignTx, false)) {
     fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
     signing_abort();
@@ -1306,12 +1311,9 @@ void signing_txack(TransactionType *tx) {
         return;
       }
 
-      if (to_spend + tx->inputs[0].amount < to_spend) {
-        fsm_sendFailure(FailureType_Failure_DataError, _("Value overflow"));
-        signing_abort();
+      if (!add_amount(&total_in, tx->inputs[0].amount)) {
         return;
       }
-      to_spend += tx->inputs[0].amount;
 
       tx_weight += tx_input_weight(coin, &tx->inputs[0]);
 #if !BITCOIN_ONLY