Merge branch 'allow-more-filenames' into 'master'

Allow all alphanumeric characters in file names

## What does this MR do?

Allow more characters in file names such as Chinese symbols.

## Why was this MR needed?

It is annoying that some files which can be uploaded using Git CLI cannot be created with the web editor.

## What are the relevant issue numbers?

fixes #20190

See merge request !8002

changelogs/unreleased/allow-more-filenames.yml

+---
+title: Allow all alphanumeric characters in file names
+merge_request: 8002
+author: winniehell

lib/gitlab/regex.rb

@@ -61,7 +61,7 @@ module Gitlab
     end
 
     def file_name_regex
-      @file_name_regex ||= /\A[a-zA-Z0-9_\-\.\@]*\z/.freeze
+      @file_name_regex ||= /\A[[[:alnum:]]_\-\.\@]*\z/.freeze
     end
 
     def file_name_regex_message
@@ -69,7 +69,7 @@ module Gitlab
     end
 
     def file_path_regex
-      @file_path_regex ||= /\A[a-zA-Z0-9_\-\.\/\@]*\z/.freeze
+      @file_path_regex ||= /\A[[[:alnum:]]_\-\.\/\@]*\z/.freeze
     end
 
     def file_path_regex_message

spec/features/projects/files/creating_a_file_spec.rb

+require 'spec_helper'
+
+feature 'User wants to create a file', feature: true do
+  include WaitForAjax
+
+  let(:project) { create(:project) }
+  let(:user) { create(:user) }
+
+  background do
+    project.team << [user, :master]
+    login_as user
+    visit namespace_project_new_blob_path(project.namespace, project, project.default_branch)
+  end
+
+  def submit_new_file(options)
+    file_name = find('#file_name')
+    file_name.set options[:file_name] || 'README.md'
+
+    file_content = find('#file-content')
+    file_content.set options[:file_content] || 'Some content'
+
+    click_button 'Commit Changes'
+  end
+
+  scenario 'file name contains Chinese characters' do
+    submit_new_file(file_name: '测试.md')
+    expect(page).to have_content 'The file has been successfully created.'
+  end
+
+  scenario 'directory name contains Chinese characters' do
+    submit_new_file(file_name: '中文/测试.md')
+    expect(page).to have_content 'The file has been successfully created.'
+  end
+
+  scenario 'file name contains invalid characters' do
+    submit_new_file(file_name: '\\')
+    expect(page).to have_content 'Your changes could not be committed, because the file name can contain only'
+  end
+
+  scenario 'file name contains directory traversal' do
+    submit_new_file(file_name: '../README.md')
+    expect(page).to have_content 'Your changes could not be committed, because the file name cannot include directory traversal.'
+  end
+end