Index: trunk/src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java	(revision 17322)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java	(revision 17323)
@@ -72,5 +72,4 @@
 import org.openstreetmap.josm.plugins.PluginHandler;
 import org.openstreetmap.josm.plugins.PluginInformation;
-import org.openstreetmap.josm.tools.CheckParameterUtil;
 import org.openstreetmap.josm.tools.GBC;
 import org.openstreetmap.josm.tools.ImageProvider;
@@ -213,4 +212,8 @@
     }
 
+    /**
+     * Panel used for preference settings.
+     * @since 4968
+     */
     public static final class PreferencePanel extends JPanel implements PreferenceTab {
         private final transient TabPreferenceSetting preferenceSetting;
@@ -218,6 +221,5 @@
         private PreferencePanel(TabPreferenceSetting preferenceSetting) {
             super(new GridBagLayout());
-            CheckParameterUtil.ensureParameterNotNull(preferenceSetting);
-            this.preferenceSetting = preferenceSetting;
+            this.preferenceSetting = Objects.requireNonNull(preferenceSetting, "preferenceSetting");
             buildPanel();
         }
@@ -249,14 +251,14 @@
     }
 
+    /**
+     * Scroll pane used for large {@link PreferencePanel}s.
+     * @since 4968
+     */
     public static final class PreferenceScrollPane extends JScrollPane implements PreferenceTab {
         private final transient TabPreferenceSetting preferenceSetting;
 
-        private PreferenceScrollPane(Component view, TabPreferenceSetting preferenceSetting) {
-            super(view);
-            this.preferenceSetting = preferenceSetting;
-        }
-
         private PreferenceScrollPane(PreferencePanel preferencePanel) {
-            this(preferencePanel.getComponent(), preferencePanel.getTabPreferenceSetting());
+            super(preferencePanel.getComponent());
+            this.preferenceSetting = preferencePanel.getTabPreferenceSetting();
             GuiHelper.setDefaultIncrement(this);
         }
@@ -312,13 +314,6 @@
      */
     public PreferencePanel createPreferenceTab(TabPreferenceSetting caller, boolean inScrollPane) {
-        CheckParameterUtil.ensureParameterNotNull(caller, "caller");
-        PreferencePanel p = new PreferencePanel(caller);
-
-        PreferenceTab tab = p;
-        if (inScrollPane) {
-            PreferenceScrollPane sp = new PreferenceScrollPane(p);
-            tab = sp;
-        }
-        tabs.add(tab);
+        PreferencePanel p = new PreferencePanel(Objects.requireNonNull(caller, "caller"));
+        tabs.add(inScrollPane ? new PreferenceScrollPane(p) : p);
         return p;
     }
Index: trunk/src/org/openstreetmap/josm/gui/preferences/server/ServerAccessPreference.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/server/ServerAccessPreference.java	(revision 17322)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/server/ServerAccessPreference.java	(revision 17323)
@@ -4,4 +4,5 @@
 import static org.openstreetmap.josm.tools.I18n.tr;
 
+import java.awt.GridBagConstraints;
 import java.awt.GridBagLayout;
 import java.beans.PropertyChangeListener;
@@ -53,14 +54,18 @@
     }
 
+    private static GBC eopFilledHorizontal() {
+        return GBC.eop().fill(GridBagConstraints.HORIZONTAL);
+    }
+
     @Override
     public void addGui(PreferenceTabbedPane gui) {
         JPanel panel = new JPanel(new GridBagLayout());
-        panel.add(pnlApiUrlPreferences, GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(new JSeparator(), GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(pnlAuthPreferences, GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(new JSeparator(), GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(pnlFeaturesPreferences, GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(new JSeparator(), GBC.eop().fill(GBC.HORIZONTAL));
-        panel.add(pnlOverpassPreferences, GBC.eop().fill(GBC.HORIZONTAL));
+        panel.add(pnlApiUrlPreferences, eopFilledHorizontal());
+        panel.add(new JSeparator(), eopFilledHorizontal());
+        panel.add(pnlAuthPreferences, eopFilledHorizontal());
+        panel.add(new JSeparator(), eopFilledHorizontal());
+        panel.add(pnlFeaturesPreferences, eopFilledHorizontal());
+        panel.add(new JSeparator(), eopFilledHorizontal());
+        panel.add(pnlOverpassPreferences, eopFilledHorizontal());
 
         pnlApiUrlPreferences.initFromPreferences();
@@ -72,5 +77,5 @@
         HelpUtil.setHelpContext(panel, HelpUtil.ht("/Preferences/Connection"));
         panel.add(Box.createVerticalGlue(), GBC.eol().fill());
-        gui.createPreferenceTab(this).add(panel, GBC.eol().fill());
+        createPreferenceTabWithScrollPane(gui, panel);
     }