Give QApplication dummy arguments

QApplication takes the command line arguments and parses them itself
for some built in command line arguments that it has. We don't want
any of those built in arguments, so instead give it dummy arguments.

src/qt/bitcoin.cpp

@@ -169,8 +169,11 @@ void BitcoinCore::shutdown()
     }
 }
 
-BitcoinApplication::BitcoinApplication(interfaces::Node& node, int &argc, char **argv):
-    QApplication(argc, argv),
+static int qt_argc = 1;
+static const char* qt_argv = "bitcoin-qt";
+
+BitcoinApplication::BitcoinApplication(interfaces::Node& node):
+    QApplication(qt_argc, const_cast<char **>(&qt_argv)),
     coreThread(nullptr),
     m_node(node),
     optionsModel(nullptr),
@@ -433,7 +436,7 @@ int GuiMain(int argc, char* argv[])
     QApplication::setAttribute(Qt::AA_DontShowIconsInMenus);
 #endif
 
-    BitcoinApplication app(*node, argc, argv);
+    BitcoinApplication app(*node);
 
     // Register meta types used for QMetaObject::invokeMethod
     qRegisterMetaType< bool* >();

src/qt/bitcoin.h

@@ -56,7 +56,7 @@ class BitcoinApplication: public QApplication
 {
     Q_OBJECT
 public:
-    explicit BitcoinApplication(interfaces::Node& node, int &argc, char **argv);
+    explicit BitcoinApplication(interfaces::Node& node);
     ~BitcoinApplication();
 
 #ifdef ENABLE_WALLET

src/qt/test/test_main.cpp

@@ -68,7 +68,7 @@ int main(int argc, char *argv[])
 
     // Don't remove this, it's needed to access
     // QApplication:: and QCoreApplication:: in the tests
-    BitcoinApplication app(*node, argc, argv);
+    BitcoinApplication app(*node);
     app.setApplicationName("Bitcoin-Qt-test");
 
     AppTests app_tests(app);