Merge bitcoin-core/gui#771: Avoid error-prone leading whitespace in translatable strings

856325f lint: Add `lint-qt-translation.py` (Hennadii Stepanov)
294a018 qt: Avoid error prone leading spaces in translatable strings (Hennadii Stepanov)
d8298e7 qt, refactor: Drop superfluous type conversions (Hennadii Stepanov)

Pull request description:

  While working on the GUI translation via Transifex web interface, I found it error-prone to have leading whitespace in translatable strings. This is because it is very easy to unintentionally drop them in translations unnoticed.

  Fixed all current cases. Added a linter to prevent similar cases in the future.

ACKs for top commit:
  furszy:
    utACK 856325f

Tree-SHA512: b1ca5effb2db6649e1e99382de79acf3a9f81cc9dad434db5623338489e597897e8addd60c1ab3dcc7506ae62753a7a4ad5a41d7a865f8fcdf94348b54baa7e7

Author: hebasto

src/qt/psbtoperationsdialog.cpp

@@ -167,19 +167,20 @@ void PSBTOperationsDialog::saveTransaction() {
 }
 
 void PSBTOperationsDialog::updateTransactionDisplay() {
-    m_ui->transactionDescription->setText(QString::fromStdString(renderTransaction(m_transaction_data)));
+    m_ui->transactionDescription->setText(renderTransaction(m_transaction_data));
     showTransactionStatus(m_transaction_data);
 }
 
-std::string PSBTOperationsDialog::renderTransaction(const PartiallySignedTransaction &psbtx)
+QString PSBTOperationsDialog::renderTransaction(const PartiallySignedTransaction &psbtx)
 {
-    QString tx_description = "";
+    QString tx_description;
+    QLatin1String bullet_point(" * ");
     CAmount totalAmount = 0;
     for (const CTxOut& out : psbtx.tx->vout) {
         CTxDestination address;
         ExtractDestination(out.scriptPubKey, address);
         totalAmount += out.nValue;
-        tx_description.append(tr(" * Sends %1 to %2")
+        tx_description.append(bullet_point).append(tr("Sends %1 to %2")
             .arg(BitcoinUnits::formatWithUnit(BitcoinUnit::BTC, out.nValue))
             .arg(QString::fromStdString(EncodeDestination(address))));
         // Check if the address is one of ours
@@ -188,7 +189,7 @@ std::string PSBTOperationsDialog::renderTransaction(const PartiallySignedTransac
     }
 
     PSBTAnalysis analysis = AnalyzePSBT(psbtx);
-    tx_description.append(" * ");
+    tx_description.append(bullet_point);
     if (!*analysis.fee) {
         // This happens if the transaction is missing input UTXO information.
         tx_description.append(tr("Unable to calculate transaction fee or total transaction amount."));
@@ -217,7 +218,7 @@ std::string PSBTOperationsDialog::renderTransaction(const PartiallySignedTransac
         tx_description.append(tr("Transaction has %1 unsigned inputs.").arg(QString::number(num_unsigned)));
     }
 
-    return tx_description.toStdString();
+    return tx_description;
 }
 
 void PSBTOperationsDialog::showStatus(const QString &msg, StatusLevel level) {

src/qt/psbtoperationsdialog.h

@@ -6,6 +6,7 @@
 #define BITCOIN_QT_PSBTOPERATIONSDIALOG_H
 
 #include <QDialog>
+#include <QString>
 
 #include <psbt.h>
 #include <qt/clientmodel.h>
@@ -46,7 +47,7 @@ public Q_SLOTS:
 
     size_t couldSignInputs(const PartiallySignedTransaction &psbtx);
     void updateTransactionDisplay();
-    std::string renderTransaction(const PartiallySignedTransaction &psbtx);
+    QString renderTransaction(const PartiallySignedTransaction &psbtx);
     void showStatus(const QString &msg, StatusLevel level);
     void showTransactionStatus(const PartiallySignedTransaction &psbtx);
 };

src/qt/sendcoinsdialog.cpp

@@ -302,7 +302,7 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
         // generate amount string with wallet name in case of multiwallet
         QString amount = BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), rcp.amount);
         if (model->isMultiwallet()) {
-            amount.append(tr(" from wallet '%1'").arg(GUIUtil::HtmlEscape(model->getWalletName())));
+            amount = tr("%1 from wallet '%2'").arg(amount, GUIUtil::HtmlEscape(model->getWalletName()));
         }
 
         // generate address string

src/qt/transactiondesc.cpp

@@ -323,7 +323,7 @@ QString TransactionDesc::toHTML(interfaces::Node& node, interfaces::Wallet& wall
             if (!GetPaymentRequestMerchant(r.second, merchant)) {
                 merchant.clear();
             } else {
-                merchant += tr(" (Certificate was not verified)");
+                merchant = tr("%1 (Certificate was not verified)").arg(merchant);
             }
             if (!merchant.isNull()) {
                 strHTML += "<b>" + tr("Merchant") + ":</b> " + GUIUtil::HtmlEscape(merchant) + "<br>";

src/qt/walletcontroller.cpp

@@ -472,10 +472,10 @@ void MigrateWalletActivity::migrate(WalletModel* wallet_model)
         if (res) {
             m_success_message = tr("The wallet '%1' was migrated successfully.").arg(GUIUtil::HtmlEscape(res->wallet->getWalletName()));
             if (res->watchonly_wallet_name) {
-                m_success_message += tr(" Watchonly scripts have been migrated to a new wallet named '%1'.").arg(GUIUtil::HtmlEscape(res->watchonly_wallet_name.value()));
+                m_success_message += QChar(' ') + tr("Watchonly scripts have been migrated to a new wallet named '%1'.").arg(GUIUtil::HtmlEscape(res->watchonly_wallet_name.value()));
             }
             if (res->solvables_wallet_name) {
-                m_success_message += tr(" Solvable but not watched scripts have been migrated to a new wallet named '%1'.").arg(GUIUtil::HtmlEscape(res->solvables_wallet_name.value()));
+                m_success_message += QChar(' ') + tr("Solvable but not watched scripts have been migrated to a new wallet named '%1'.").arg(GUIUtil::HtmlEscape(res->solvables_wallet_name.value()));
             }
             m_wallet_model = m_wallet_controller->getOrCreateWallet(std::move(res->wallet));
         } else {

test/lint/lint-qt-translation.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2023-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+#
+# Check for leading whitespaces in the translatable strings.
+
+import subprocess
+import sys
+
+
+def main():
+    tr_strings = subprocess.run(['git', 'grep', '-e', 'tr("[[:space:]]', '--', 'src/qt'], stdout=subprocess.PIPE, text=True).stdout
+
+    if tr_strings.strip():
+        print("Avoid leading whitespaces in:")
+        print(tr_strings)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()