AMBARI-3840 Delete should be disabled if there is no group selected. (atkach)
diff --git a/ambari-web/app/controllers/main/service/item.js b/ambari-web/app/controllers/main/service/item.js
index 5843eba..350318b 100644
--- a/ambari-web/app/controllers/main/service/item.js
+++ b/ambari-web/app/controllers/main/service/item.js
@@ -279,14 +279,17 @@
       updateConfigGroupOnServicePage: function () {
         var mainServiceInfoConfigsController = App.get('router.mainServiceInfoConfigsController');
         var selectedConfigGroup = mainServiceInfoConfigsController.get('selectedConfigGroup');
-        var managedConfigGroups = this.get('subViewController.configGroups');
-        selectedConfigGroup = managedConfigGroups.findProperty('id', selectedConfigGroup.id);
-        if(selectedConfigGroup){
-          mainServiceInfoConfigsController.set('selectedConfigGroup', selectedConfigGroup);
-        }else{
-          mainServiceInfoConfigsController.set('selectedConfigGroup',  managedConfigGroups.findProperty('isDefault', true));
+        //check whether selectedConfigGroup was selected
+        if (selectedConfigGroup) {
+          var managedConfigGroups = this.get('subViewController.configGroups');
+          selectedConfigGroup = managedConfigGroups.findProperty('id', selectedConfigGroup.id);
+          if (selectedConfigGroup) {
+            mainServiceInfoConfigsController.set('selectedConfigGroup', selectedConfigGroup);
+          } else {
+            mainServiceInfoConfigsController.set('selectedConfigGroup', managedConfigGroups.findProperty('isDefault', true));
+          }
         }
-        mainServiceInfoConfigsController.set('configGroups',this.get('subViewController.configGroups'));
+        mainServiceInfoConfigsController.set('configGroups', this.get('subViewController.configGroups'));
       },
       updateButtons: function(){
         var modified = this.get('subViewController.isHostsModified');
diff --git a/ambari-web/app/controllers/main/service/manage_config_groups_controller.js b/ambari-web/app/controllers/main/service/manage_config_groups_controller.js
index 2c0018e..acd7f96 100644
--- a/ambari-web/app/controllers/main/service/manage_config_groups_controller.js
+++ b/ambari-web/app/controllers/main/service/manage_config_groups_controller.js
@@ -195,18 +195,18 @@
    */
   deleteConfigGroup: function () {
     var selectedConfigGroup = this.get('selectedConfigGroup');
-    if(selectedConfigGroup.get('name') == "Default") {
+    if (this.get('isDeleteGroupDisabled')) {
       return;
     }
-      App.ajax.send({
-        name: 'config_groups.delete_config_group',
-        sender: this,
-        data: {
-          id: selectedConfigGroup.get('id')
-        }
-      });
-      this.get('configGroups').removeObject(selectedConfigGroup);
-
+    App.ajax.send({
+      name: 'config_groups.delete_config_group',
+      sender: this,
+      data: {
+        id: selectedConfigGroup.get('id')
+      }
+    });
+    this.get('configGroups').removeObject(selectedConfigGroup);
+    this.set('selectedConfigGroup', this.get('configGroups').findProperty('isDefault'));
   },
 
   /**
@@ -383,5 +383,9 @@
   isHostsModified: function () {
     var groups = this.get('hostsModifiedConfigGroups');
     return groups && groups.length > 0;
-  }.property('hostsModifiedConfigGroups', 'hostsModifiedConfigGroups.length')
+  }.property('hostsModifiedConfigGroups', 'hostsModifiedConfigGroups.length'),
+
+  isDeleteGroupDisabled: function () {
+    return this.get('selectedConfigGroup.isDefault');
+  }.property('selectedConfigGroup')
 });
diff --git a/ambari-web/app/templates/main/service/manage_configuration_groups_popup.hbs b/ambari-web/app/templates/main/service/manage_configuration_groups_popup.hbs
index 6194b84..9ee572e 100644
--- a/ambari-web/app/templates/main/service/manage_configuration_groups_popup.hbs
+++ b/ambari-web/app/templates/main/service/manage_configuration_groups_popup.hbs
@@ -30,7 +30,7 @@
         }}
         <div class="btn-toolbar pull-right">
           <button class="btn" {{bindAttr disabled="isHostsModified"}} {{action addConfigGroup target="controller"}}><i class="icon-plus"></i></button>
-          <button class="btn" {{bindAttr disabled="view.isRemoveButtonDisabled"}} {{action deleteConfigGroup target="controller"}}><i class="icon-minus"></i></button>
+          <button class="btn" {{bindAttr disabled="isDeleteGroupDisabled"}} {{action deleteConfigGroup target="controller"}}><i class="icon-minus"></i></button>
           <div class="btn-group">
             <button class="btn" {{bindAttr disabled="isHostsModified"}}><i class="icon-cog"></i></button>
             <button class="btn dropdown-toggle" data-toggle="dropdown" {{bindAttr disabled="isHostsModified"}}>