Don't allow duplicate address labels

src/chatmodel.cpp

@@ -237,6 +237,20 @@ void MainWindow::renderContactRequest(){
             return;
         }
 
+         // Don't allow duplicate address labels.      
+                  
+        if (!AddressBook::getInstance()->getAddressForLabel(newLabel).isEmpty()) 
+        {
+            QMessageBox::critical(
+                this, 
+                QObject::tr("Label Error"), 
+                QObject::tr("The label '%1' already exists. Please remove the existing label.").arg(newLabel), 
+                QMessageBox::Ok
+            );
+            qDebug()<<"Doppelter Name";
+            return;
+        }
+
         // Test if address is valid.
         if (!Settings::isValidAddress(addr)) 
         {
@@ -248,6 +262,9 @@ void MainWindow::renderContactRequest(){
             );
             return;
         } 
+
+       
+        
         AddressBook::getInstance()->addAddressLabel(newLabel, addr, myAddr, cid, avatar);
         rpc->refreshContacts(
         ui->listContactWidget);
@@ -829,6 +846,19 @@ void MainWindow::ContactRequest() {
         return;
     }
     
+    QString newLabel = contactRequest.getLabel();
+
+        if (!AddressBook::getInstance()->getAddressForLabel(newLabel).isEmpty()) 
+        {
+            QMessageBox::critical(
+                this, 
+                QObject::tr("Label Error"), 
+                QObject::tr("The label '%1' already exists. Please remove the existing label.").arg(newLabel), 
+                QMessageBox::Ok
+            );
+            return;
+        }
+
     int max = 512;
     QString chattext = contactRequest.getMemo();;
     int size = chattext.size();
@@ -916,6 +946,17 @@ void MainWindow::ContactRequest() {
             return;
         }
 
+         if (!AddressBook::getInstance()->getAddressForLabel(newLabel).isEmpty()) 
+        {
+            QMessageBox::critical(
+                this, 
+                QObject::tr("Label Error"), 
+                QObject::tr("The label '%1' already exists. Please remove the existing label.").arg(newLabel), 
+                QMessageBox::Ok
+            );
+            return;
+        }
+
         // Test if address is valid.
         if (!Settings::isValidAddress(addr)) 
         {
@@ -928,8 +969,6 @@ void MainWindow::ContactRequest() {
             return;
         } 
 
-        ///////Todo: Test if label allready exist!
-
         ////// Success, so show it
         AddressBook::getInstance()->addAddressLabel(newLabel, addr, myAddr, cid, avatar);
         rpc->refreshContacts(