Merge bitcoin-core/gui#806: refactor: Misc int sign change fixes

0541642 refactor: Avoid implicit-integer-sign-change in processNewTransaction (MarcoFalke)
321f105 refactor: Avoid implicit-signed-integer-truncation-or-sign-change in FreedesktopImage (MarcoFalke)
6d8eecd refactor: Avoid implicit-integer-sign-change in createTransaction (MarcoFalke)

Pull request description:

  This is allowed by the language. However, the `integer` sanitizer complains about it. Thus, fix it, so that the `integer` sanitizer can be used in the future to catch unintended sign changes.

  Fixes bitcoin#805.

ACKs for top commit:
  pablomartin4btc:
    tACK 0541642
  hebasto:
    ACK 0541642, I have reviewed the code and it looks OK.

Tree-SHA512: eaa941479bd7bee196eb8b31d93b8e1db122410cf62e8ec4cbbec35cfd14cc766081c3df5dd14a228e21ad2678d8b8ba0d2649e5934c994a90ae96d8b264b4ce

Author: hebasto

src/qt/notificator.cpp

@@ -112,10 +112,10 @@ FreedesktopImage::FreedesktopImage(const QImage &img):
 
     for(unsigned int ptr = 0; ptr < num_pixels; ++ptr)
     {
-        image[ptr*BYTES_PER_PIXEL+0] = data[ptr] >> 16; // R
-        image[ptr*BYTES_PER_PIXEL+1] = data[ptr] >> 8;  // G
-        image[ptr*BYTES_PER_PIXEL+2] = data[ptr];       // B
-        image[ptr*BYTES_PER_PIXEL+3] = data[ptr] >> 24; // A
+        image[ptr * BYTES_PER_PIXEL + 0] = char(data[ptr] >> 16); // R
+        image[ptr * BYTES_PER_PIXEL + 1] = char(data[ptr] >> 8);  // G
+        image[ptr * BYTES_PER_PIXEL + 2] = char(data[ptr]);       // B
+        image[ptr * BYTES_PER_PIXEL + 3] = char(data[ptr] >> 24); // A
     }
 }
 

src/qt/walletview.cpp

@@ -134,7 +134,7 @@ void WalletView::processNewTransaction(const QModelIndex& parent, int start, int
         return;
 
     QString date = ttm->index(start, TransactionTableModel::Date, parent).data().toString();
-    qint64 amount = ttm->index(start, TransactionTableModel::Amount, parent).data(Qt::EditRole).toULongLong();
+    qint64 amount = ttm->index(start, TransactionTableModel::Amount, parent).data(Qt::EditRole).toLongLong();
     QString type = ttm->index(start, TransactionTableModel::Type, parent).data().toString();
     QModelIndex index = ttm->index(start, 0, parent);
     QString address = ttm->data(index, TransactionTableModel::AddressRole).toString();

src/wallet/interfaces.cpp

@@ -286,7 +286,7 @@ class WalletImpl : public Wallet
         if (!res) return util::Error{util::ErrorString(res)};
         const auto& txr = *res;
         fee = txr.fee;
-        change_pos = txr.change_pos ? *txr.change_pos : -1;
+        change_pos = txr.change_pos ? int(*txr.change_pos) : -1;
 
         return txr.tx;
     }