[Qt] ensure all class attributes are init to 0

- in BitcoinGUI and UnitDisplayStatusBarControl

src/qt/bitcoingui.cpp

@@ -61,9 +61,33 @@ BitcoinGUI::BitcoinGUI(bool fIsTestnet, QWidget *parent) :
     QMainWindow(parent),
     clientModel(0),
     walletFrame(0),
+    unitDisplayControl(0),
+    labelEncryptionIcon(0),
+    labelConnectionsIcon(0),
+    labelBlocksIcon(0),
+    progressBarLabel(0),
+    progressBar(0),
+    progressDialog(0),
+    appMenuBar(0),
+    overviewAction(0),
+    historyAction(0),
+    quitAction(0),
+    sendCoinsAction(0),
+    usedSendingAddressesAction(0),
+    usedReceivingAddressesAction(0),
+    signMessageAction(0),
+    verifyMessageAction(0),
+    aboutAction(0),
+    receiveCoinsAction(0),
+    optionsAction(0),
+    toggleHideAction(0),
     encryptWalletAction(0),
+    backupWalletAction(0),
     changePassphraseAction(0),
     aboutQtAction(0),
+    openRPCConsoleAction(0),
+    openAction(0),
+    showHelpMessageAction(0),
     trayIcon(0),
     notificator(0),
     rpcConsole(0),
@@ -1006,9 +1030,10 @@ void BitcoinGUI::unsubscribeFromCoreSignals()
     uiInterface.ThreadSafeMessageBox.disconnect(boost::bind(ThreadSafeMessageBox, this, _1, _2, _3));
 }
 
-UnitDisplayStatusBarControl::UnitDisplayStatusBarControl():QLabel()
+UnitDisplayStatusBarControl::UnitDisplayStatusBarControl() :
+    optionsModel(0),
+    menu(0)
 {
-    optionsModel = 0;
     createContextMenu();
     setToolTip(tr("Unit to show amounts in. Click to select another unit."));
 }
@@ -1068,4 +1093,3 @@ void UnitDisplayStatusBarControl::onMenuSelection(QAction* action)
         optionsModel->setDisplayUnit(action->data());
     }
 }
-

src/qt/bitcoingui.h

@@ -219,6 +219,7 @@ protected:
 private:
     OptionsModel *optionsModel;
     QMenu* menu;
+
     /** Shows context menu with Display Unit options by the mouse coordinates */
     void onDisplayUnitsClicked(const QPoint& point);
     /** Creates context menu, its actions, and wires up all the relevant signals for mouse events. */