Index: /trunk/src/org/openstreetmap/josm/data/oauth/OAuthParameters.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/oauth/OAuthParameters.java	(revision 6581)
+++ /trunk/src/org/openstreetmap/josm/data/oauth/OAuthParameters.java	(revision 6582)
@@ -91,5 +91,5 @@
      */
     static public OAuthParameters createFromPreferences(Preferences pref) {
-        OAuthParameters parameters = createDefault(pref.get("osm-server.url"));
+        OAuthParameters parameters = createDefault(pref.get("osm-server.url", OsmApi.DEFAULT_API_URL));
         parameters.setConsumerKey(pref.get("oauth.settings.consumer-key", parameters.getConsumerKey()));
         parameters.setConsumerSecret(pref.get("oauth.settings.consumer-secret", parameters.getConsumerSecret()));
Index: /trunk/src/org/openstreetmap/josm/gui/oauth/OsmOAuthAuthorizationClient.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/oauth/OsmOAuthAuthorizationClient.java	(revision 6581)
+++ /trunk/src/org/openstreetmap/josm/gui/oauth/OsmOAuthAuthorizationClient.java	(revision 6582)
@@ -35,4 +35,5 @@
 import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
 import org.openstreetmap.josm.gui.progress.ProgressMonitor;
+import org.openstreetmap.josm.io.OsmApi;
 import org.openstreetmap.josm.io.OsmTransferCanceledException;
 import org.openstreetmap.josm.tools.CheckParameterUtil;
@@ -61,5 +62,5 @@
      */
     public OsmOAuthAuthorizationClient() {
-        oauthProviderParameters = OAuthParameters.createDefault(Main.pref.get("osm-server.url"));
+        oauthProviderParameters = OAuthParameters.createDefault(Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL));
         consumer = oauthProviderParameters.buildConsumer();
         provider = oauthProviderParameters.buildProvider(consumer);
Index: /trunk/src/org/openstreetmap/josm/gui/preferences/server/OsmApiUrlInputPanel.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/preferences/server/OsmApiUrlInputPanel.java	(revision 6581)
+++ /trunk/src/org/openstreetmap/josm/gui/preferences/server/OsmApiUrlInputPanel.java	(revision 6582)
@@ -128,9 +128,6 @@
      */
     public void initFromPreferences() {
-        String url =  Main.pref.get("osm-server.url", null);
-        if (url == null) {
-            cbUseDefaultServerUrl.setSelected(true);
-            firePropertyChange(API_URL_PROP, null, OsmApi.DEFAULT_API_URL);
-        } else if (url.trim().equals(OsmApi.DEFAULT_API_URL)) {
+        String url =  Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL);
+        if (url.trim().equals(OsmApi.DEFAULT_API_URL)) {
             cbUseDefaultServerUrl.setSelected(true);
             firePropertyChange(API_URL_PROP, null, OsmApi.DEFAULT_API_URL);
@@ -146,5 +143,5 @@
      */
     public void saveToPreferences() {
-        String old_url = Main.pref.get("osm-server.url", null);
+        String old_url = Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL);
         if (cbUseDefaultServerUrl.isSelected()) {
             Main.pref.put("osm-server.url", null);
@@ -154,9 +151,9 @@
             Main.pref.put("osm-server.url", tfOsmServerUrl.getText().trim());
         }
-        String new_url = Main.pref.get("osm-server.url", null);
+        String new_url = Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL);
 
         // When API URL changes, re-initialize API connection so we may adjust
         // server-dependent settings.
-        if ((old_url == null && new_url != null) || (old_url != null && !old_url.equals(new_url))) {
+        if (!old_url.equals(new_url)) {
             try {
                 OsmApi.getOsmApi().initialize(null);
Index: /trunk/src/org/openstreetmap/josm/io/OsmApi.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/io/OsmApi.java	(revision 6581)
+++ /trunk/src/org/openstreetmap/josm/io/OsmApi.java	(revision 6582)
@@ -99,11 +99,7 @@
      *
      * @return the OsmApi
-     * @throws IllegalStateException thrown, if the preference <code>osm-server.url</code> is not set
-     *
      */
     static public OsmApi getOsmApi() {
         String serverUrl = Main.pref.get("osm-server.url", DEFAULT_API_URL);
-        if (serverUrl == null)
-            throw new IllegalStateException(tr("Preference ''{0}'' missing. Cannot initialize OsmApi.", "osm-server.url"));
         return getOsmApi(serverUrl);
     }
Index: /trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java	(revision 6581)
+++ /trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java	(revision 6582)
@@ -52,6 +52,6 @@
         String msg = tr(
                 "<html>Failed to initialize communication with the OSM server {0}.<br>"
-                + "Check the server URL in your preferences and your internet connection.", Main.pref.get(
-                        "osm-server.url", OsmApi.DEFAULT_API_URL));
+                + "Check the server URL in your preferences and your internet connection.",
+                Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL));
         return msg;
     }