Bitcoin-Qt: extend some checks for valid model pointers

src/qt/sendcoinsdialog.cpp

@@ -39,16 +39,17 @@ void SendCoinsDialog::setModel(WalletModel *model)
 {
     this->model = model;
 
-    for(int i = 0; i < ui->entries->count(); ++i)
+    if(model && model->getOptionsModel())
     {
-        SendCoinsEntry *entry = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(i)->widget());
+        for(int i = 0; i < ui->entries->count(); ++i)
-        if(entry)
         {
-            entry->setModel(model);
+            SendCoinsEntry *entry = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(i)->widget());
+            if(entry)
+            {
+                entry->setModel(model);
+            }
         }
-    }
+
-    if(model && model->getOptionsModel())
-    {
         setBalance(model->getBalance(), model->getUnconfirmedBalance(), model->getImmatureBalance());
         connect(model, SIGNAL(balanceChanged(qint64, qint64, qint64)), this, SLOT(setBalance(qint64, qint64, qint64)));
         connect(model->getOptionsModel(), SIGNAL(displayUnitChanged(int)), this, SLOT(updateDisplayUnit()));

src/qt/signverifymessagedialog.cpp

@@ -102,6 +102,9 @@ void SignVerifyMessageDialog::on_pasteButton_SM_clicked()
 
 void SignVerifyMessageDialog::on_signMessageButton_SM_clicked()
 {
+    if (!model)
+        return;
+
     /* Clear old signature to ensure users don't get confused on error with an old signature displayed */
     ui->signatureOut_SM->clear();