Fix --output path with specified folder

lib/vagrant/action/general/package.rb

@@ -73,6 +73,8 @@ module Vagrant
 
           self.class.validate!(env["package.output"], env["package.directory"])
 
+          package_with_folder_path if env["package.output"].include?(File::SEPARATOR)
+
           raise Errors::PackageOutputDirectory if File.directory?(fullpath)
 
           @app.call(env)
@@ -83,6 +85,16 @@ module Vagrant
           compress
         end
 
+        def package_with_folder_path
+          folder_path = File.expand_path("..", @fullpath)
+          create_box_folder(folder_path) unless File.directory?(folder_path)
+        end
+
+        def create_box_folder(folder_path)
+          @env[:ui].info(I18n.t("vagrant.actions.general.package.box_folder", folder_path: folder_path))
+          FileUtils.mkdir_p(folder_path)
+        end
+
         def recover(env)
           @env = env
 

templates/locales/en.yml

@@ -2114,6 +2114,7 @@ en:
         package:
           packaging: "Packaging additional file: %{file}"
           compressing: "Compressing package to: %{fullpath}"
+          box_folder: "Creating new folder: %{folder_path}"
           output_exists: |-
             The specified file '%{filename}' to save the package as already exists. Please
             remove this file or specify a different file name for outputting.

test/unit/plugins/commands/package/command_test.rb

@@ -57,6 +57,18 @@ describe VagrantPlugins::CommandPackage::Command do
           expect{ package_command.execute }.to raise_error(Vagrant::Errors::MachineNotFound)
         end
       end
+
+      context "with --output option" do
+
+        let(:argv){ ['--output', 'package-output-folder/default'] }
+
+        it "packages default machine inside specified folder" do
+          expect(package_command).to receive(:package_vm).with(
+            a_machine_named('default'), :output => "package-output-folder/default"
+          )
+          package_command.execute
+        end
+      end
     end
 
     context "with multiple arguments" do