1 files changed, 26 insertions, 5 deletions
diff --git a/app/controllers/groups/milestones_controller.rb b/app/controllers/groups/milestones_controller.rb
index b23c3022fb5..9d5a28e8d4d 100644
--- a/app/controllers/groups/milestones_controller.rb
+++ b/app/controllers/groups/milestones_controller.rb
@@ -18,14 +18,14 @@ class Groups::MilestonesController < Groups::ApplicationController
   end
 
   def create
-    project_ids = params[:milestone][:project_ids]
+    project_ids = params[:milestone][:project_ids].reject(&:blank?)
     title = milestone_params[:title]
 
-    @projects.where(id: project_ids).each do |project|
-      Milestones::CreateService.new(project, current_user, milestone_params).execute
+    if create_milestones(project_ids)
+      redirect_to milestone_path(title)
+    else
+      render_new_with_error(project_ids.empty?)
     end
-
-    redirect_to milestone_path(title)
   end
 
   def show
@@ -41,6 +41,27 @@ class Groups::MilestonesController < Groups::ApplicationController
 
   private
 
+  def create_milestones(project_ids)
+    return false unless project_ids.present?
+
+    ActiveRecord::Base.transaction do
+      @projects.where(id: project_ids).each do |project|
+        Milestones::CreateService.new(project, current_user, milestone_params).execute
+      end
+    end
+
+    true
+  rescue ActiveRecord::ActiveRecordError => e
+    flash.now[:alert] = "An error occurred while creating the milestone: #{e.message}"
+    false
+  end
+
+  def render_new_with_error(empty_project_ids)
+    @milestone = Milestone.new(milestone_params)
+    @milestone.errors.add(:project_id, "Please select at least one project.") if empty_project_ids
+    render :new
+  end
+
   def authorize_admin_milestones!
     return render_404 unless can?(current_user, :admin_milestones, group)
   end