Fix ConcurrentModificationException on designer

It was triggered when restoring multiple properties,
since the items where added to a collection that was
being iterated.

Also fix a small bug when creating a property named
TODO -> the next property was allowed to be called
TODO if the name wasn't changed, since the name field
wasn't changed, so didn't trigger reevaluation of the
validators.

pmd-ui/src/main/java/net/sourceforge/pmd/util/fxdesigner/EditPropertyDialogController.java

@@ -115,6 +115,7 @@ public class EditPropertyDialogController implements Initializable {
         backingDescriptor.ifPresent(PropertyDescriptorSpec::unbind);
         backingDescriptor.setValue(null);
         backingDescriptorList.setValue(null);
+        this.nameProperty().setValue(""); // necessary to get the validator to reevaluate each time
     }
 
 

pmd-ui/src/main/java/net/sourceforge/pmd/util/fxdesigner/util/DesignerUtil.java

@@ -157,14 +157,13 @@ public final class DesignerUtil {
      */
     public static <T> void rewire(Property<T> underlying, ObservableValue<? extends T> ui, Consumer<? super T> setter) {
         setter.accept(underlying.getValue());
-        underlying.unbind();
-        underlying.bind(ui); // Bindings are garbage collected after the popup dies
+        rewire(underlying, ui);
     }
     
     /** Like rewire, with no initialisation. */
     public static <T> void rewire(Property<T> underlying, ObservableValue<? extends T> source) {
         underlying.unbind();
-        underlying.bind(source);
+        underlying.bind(source); // Bindings are garbage collected after the popup dies
     }
 
 

pmd-ui/src/main/java/net/sourceforge/pmd/util/fxdesigner/util/beans/RestorePropertyVisitor.java

@@ -6,9 +6,11 @@ package net.sourceforge.pmd.util.fxdesigner.util.beans;
 
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.stream.Collectors;
@@ -90,6 +92,9 @@ public class RestorePropertyVisitor extends BeanNodeVisitor<SettingsOwner> {
 
         Iterator<SettingsOwner> existingItems = container.iterator();
         Class<?> itemType = null;
+        // use a buffer to avoid concurrent modification
+        List<SettingsOwner> itemsToAdd = new ArrayList<>();
+
         for (SimpleBeanModelNode child : model.getChildrenNodes()) {
             SettingsOwner item;
             if (existingItems.hasNext()) {
@@ -108,9 +113,11 @@ public class RestorePropertyVisitor extends BeanNodeVisitor<SettingsOwner> {
             }
 
             child.accept(this, item);
-            container.add(item);
+            itemsToAdd.add(item);
         }
 
+        container.addAll(itemsToAdd);
+
         try {
             PropertyUtils.setProperty(target, model.getPropertyName(), container);
         } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {