Merge #16263: qt: Use qInfo() if no error occurs

a2aabfb Use qInfo() if no error occurs (Hennadii Stepanov)

Pull request description:

  [Warning and Debugging Messages](https://doc.qt.io/qt-5/debug.html#warning-and-debugging-messages):
  > - `qInfo()` is used for informational messages.
  > - `qWarning()` is used to report warnings and recoverable errors in your
  application.
  >
  > If the `QT_FATAL_WARNINGS` environment variable is set, `qWarning()` exits after printing the warning message. This makes it easy to obtain a backtrace in the debugger.

  [`qWarning()`](https://doc.qt.io/qt-5/qtglobal.html#qWarning):
  > Calls the message handler with the warning message message... This function does nothing if `QT_NO_WARNING_OUTPUT` was defined during compilation; it exits if at the nth warning corresponding to the counter in environment variable `QT_FATAL_WARNINGS`.

  This PR allows more productive debugging using the environment variable `QT_FATAL_WARNINGS`.

  Examples:
  - bitcoin/bitcoin#16118 (comment)
  - bitcoin/bitcoin#16254 (comment)

  The behavior, when option `-debug=qt` is set/unset, remains unchanged.

ACKs for commit a2aabf:
  promag:
    ACK a2aabfb, I also have this change locally.
  Empact:
    ACK bitcoin/bitcoin@a2aabfb
  laanwj:
    ACK a2aabfb
  fanquake:
    ACK a2aabfb.

Tree-SHA512: b4df300c9c00a1705b0d3a10227e3deaac19a98b0a898bb60d5a88872cf450fb131eba150d9dd6c29e021566ee04b3b86b7d486bbe28bd894743c128d2309155

Author: fanquake

src/qt/bitcoin.cpp

@@ -330,7 +330,7 @@ void BitcoinApplication::initializeResult(bool success)
     if(success)
     {
         // Log this only after AppInitMain finishes, as then logging setup is guaranteed complete
-        qWarning() << "Platform customization:" << platformStyle->getName();
+        qInfo() << "Platform customization:" << platformStyle->getName();
 #ifdef ENABLE_WALLET
         m_wallet_controller = new WalletController(m_node, platformStyle, optionsModel, this);
 #ifdef ENABLE_BIP70

src/qt/optionsmodel.cpp

@@ -172,7 +172,7 @@ static void CopySettings(QSettings& dst, const QSettings& src)
 /** Back up a QSettings to an ini-formatted file. */
 static void BackupSettings(const fs::path& filename, const QSettings& src)
 {
-    qWarning() << "Backing up GUI settings to" << GUIUtil::boostPathToQString(filename);
+    qInfo() << "Backing up GUI settings to" << GUIUtil::boostPathToQString(filename);
     QSettings dst(GUIUtil::boostPathToQString(filename), QSettings::IniFormat);
     dst.clear();
     CopySettings(dst, src);

src/qt/paymentserver.cpp

@@ -488,7 +488,7 @@ void PaymentServer::LoadRootCAs(X509_STORE* _store)
             continue;
         }
     }
-    qWarning() << "PaymentServer::LoadRootCAs: Loaded " << nRootCerts << " root certificates";
+    qInfo() << "PaymentServer::LoadRootCAs: Loaded " << nRootCerts << " root certificates";
 
     // Project for another day:
     // Fetch certificate revocation lists, and add them to certStore.

src/qt/winshutdownmonitor.cpp

@@ -63,7 +63,7 @@ void WinShutdownMonitor::registerShutdownBlockReason(const QString& strReason, c
     }
 
     if (shutdownBRCreate(mainWinId, strReason.toStdWString().c_str()))
-        qWarning() << "registerShutdownBlockReason: Successfully registered: " + strReason;
+        qInfo() << "registerShutdownBlockReason: Successfully registered: " + strReason;
     else
         qWarning() << "registerShutdownBlockReason: Failed to register: " + strReason;
 }