Don't allow the admin group to be renamed

Renaming the admin group may cause loss of access to site admin
functions, and would permit another group owner to rename his
group to "admin", gaining those permissions.

Signed-off-by: Shawn O. Pearce <sop@google.com>

appjar/src/main/java/com/google/gerrit/client/admin/AccountGroupScreen.java

@@ -30,6 +30,7 @@ import com.google.gwt.user.client.ui.ClickListener;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.FocusListenerAdapter;
 import com.google.gwt.user.client.ui.Label;
+import com.google.gwt.user.client.ui.Panel;
 import com.google.gwt.user.client.ui.SourcesTableEvents;
 import com.google.gwt.user.client.ui.SuggestBox;
 import com.google.gwt.user.client.ui.TableListener;
@@ -48,6 +49,7 @@ public class AccountGroupScreen extends AccountScreen {
   private AccountInfoCache accounts = AccountInfoCache.empty();
   private MemberTable members;
 
+  private Panel groupNamePanel; 
   private TextBox groupNameTxt;
   private Button saveName;
 
@@ -100,11 +102,10 @@ public class AccountGroupScreen extends AccountScreen {
   }
 
   private void initName() {
-    final VerticalPanel vp = new VerticalPanel();
+    groupNamePanel = new VerticalPanel();
-
     groupNameTxt = new TextBox();
     groupNameTxt.setVisibleLength(60);
-    vp.add(groupNameTxt);
+    groupNamePanel.add(groupNameTxt);
 
     saveName = new Button(Util.C.buttonRenameGroup());
     saveName.addClickListener(new ClickListener() {
@@ -119,8 +120,8 @@ public class AccountGroupScreen extends AccountScreen {
             });
       }
     });
-    vp.add(saveName);
+    groupNamePanel.add(saveName);
-    add(vp);
+    add(groupNamePanel);
 
     new TextSaveButtonListener(groupNameTxt, saveName);
   }
@@ -209,6 +210,13 @@ public class AccountGroupScreen extends AccountScreen {
   }
 
   private void display(final AccountGroupDetail result) {
+    if (GroupAdminService.ADMIN_GROUP.equals(result.group.getNameKey())) {
+      groupNameTxt.setEnabled(false);
+      groupNamePanel.setVisible(false);
+    } else {
+      groupNamePanel.setVisible(true);
+    }
+    
     setTitleText(Util.M.group(result.group.getName()));
     groupNameTxt.setText(result.group.getName());
     descTxt.setText(result.group.getDescription());

appjar/src/main/java/com/google/gerrit/client/admin/GroupAdminServiceImpl.java

@@ -104,7 +104,15 @@ public class GroupAdminServiceImpl extends BaseServiceImplementation implements
         if (group == null) {
           throw new Failure(new NoSuchEntityException());
         }
+
         final AccountGroup.NameKey nameKey = new AccountGroup.NameKey(newName);
+        if (group.getName().equals(ADMIN_GROUP) || nameKey.equals(ADMIN_GROUP)) {
+          // Forbid renaming the admin group, its highly special because it
+          // has near root level access to the server, based upon its name.
+          //
+          throw new Failure(new NameAlreadyUsedException());
+        }
+
         if (!nameKey.equals(group.getNameKey())) {
           if (db.accountGroups().get(nameKey) != null) {
             throw new Failure(new NameAlreadyUsedException());