Index: /trunk/src/org/openstreetmap/josm/gui/oauth/AbstractAuthorizationUI.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/oauth/AbstractAuthorizationUI.java	(revision 10188)
+++ /trunk/src/org/openstreetmap/josm/gui/oauth/AbstractAuthorizationUI.java	(revision 10189)
@@ -22,9 +22,12 @@
 
     private String apiUrl;
-    private final AdvancedOAuthPropertiesPanel pnlAdvancedProperties;
+    private final AdvancedOAuthPropertiesPanel pnlAdvancedProperties = new AdvancedOAuthPropertiesPanel();
     private transient OAuthToken accessToken;
 
-    protected void fireAccessTokenChanged(OAuthToken oldValue, OAuthToken newValue) {
-        firePropertyChange(ACCESS_TOKEN_PROP, oldValue, newValue);
+    /**
+     * Constructs a new {@code AbstractAuthorizationUI} without API URL.
+     * @since 10189
+     */
+    public AbstractAuthorizationUI() {
     }
 
@@ -35,6 +38,9 @@
      */
     public AbstractAuthorizationUI(String apiUrl) {
-        pnlAdvancedProperties = new AdvancedOAuthPropertiesPanel();
         setApiUrl(apiUrl);
+    }
+
+    protected void fireAccessTokenChanged(OAuthToken oldValue, OAuthToken newValue) {
+        firePropertyChange(ACCESS_TOKEN_PROP, oldValue, newValue);
     }
 
Index: /trunk/src/org/openstreetmap/josm/gui/oauth/ManualAuthorizationUI.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/oauth/ManualAuthorizationUI.java	(revision 10188)
+++ /trunk/src/org/openstreetmap/josm/gui/oauth/ManualAuthorizationUI.java	(revision 10189)
@@ -55,5 +55,6 @@
      */
     public ManualAuthorizationUI(String apiUrl, Executor executor) {
-        super(apiUrl);
+        super(/* dont pass apiURL because setApiUrl is overriden and references a local field */);
+        setApiUrl(apiUrl);
         this.executor = executor;
         build();