Merge branch 'fix/import-controller-error' into 'master'

Fixes 404 redirect after validation fails importing a project

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19558

See merge request !5143

CHANGELOG

@@ -48,6 +48,7 @@ v 8.10.0 (unreleased)
   - Allow '?', or '&' for label names
   - Fix importer for GitHub Pull Requests when a branch was reused across Pull Requests
   - Add date when user joined the team on the member page
+  - Fix 404 redirect after validation fails importing a GitLab project
 v 8.9.5
   - Add more debug info to import/export and memory killer. !5108

app/controllers/import/gitlab_projects_controller.rb

@@ -27,10 +27,7 @@ class Import::GitlabProjectsController < Import::BaseController
         notice: "Project '#{@project.name}' is being imported."
       )
     else
-      redirect_to(
-        new_import_gitlab_project_path,
-        alert: "Project could not be imported: #{@project.errors.full_messages.join(', ')}"
-      )
+      redirect_back_or_default(options: { alert: "Project could not be imported: #{@project.errors.full_messages.join(', ')}" })
     end
   end

spec/features/projects/import_export/import_file_spec.rb

@@ -42,6 +42,23 @@ feature 'project import', feature: true, js: true do
     expect(project.import_status).to eq('finished')
   end
+  scenario 'invalid project' do
+    project = create(:project, namespace_id: 2)
+
+    visit new_project_path
+
+    select2('2', from: '#project_namespace_id')
+    fill_in :project_path, with: project.name, visible: true
+    click_link 'GitLab export'
+
+    attach_file('file', file)
+    click_on 'Import project'
+
+    page.within('.flash-container') do
+      expect(page).to have_content('Project could not be imported')
+    end
+  end
+
   def wiki_exists?
     wiki = ProjectWiki.new(project)
     File.exist?(wiki.repository.path_to_repo) && !wiki.repository.empty?