Merge branch 'dz-allow-nested-group-routing' into 'master'

Add nested groups support to the routing

## What does this MR do?

It allows routing with `/` in namespace name 

## Why was this MR needed?

For nested groups feature(https://gitlab.com/gitlab-org/gitlab-ce/issues/2772). We need URI like `/group/subgroup/project` be routed correctly


## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- ~~API support added~~
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/2772

See merge request !7459

5 files changed, 37 insertions, 37 deletions

diff --git a/lib/constraints/constrainer_helper.rb b/lib/constraints/constrainer_helper.rb
deleted file mode 100644
index ab07a6793d9..00000000000
--- a/lib/constraints/constrainer_helper.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-module ConstrainerHelper
-  def extract_resource_path(path)
-    id = path.dup
-    id.sub!(/\A#{relative_url_root}/, '') if relative_url_root
-    id.sub(/\A\/+/, '').sub(/\/+\z/, '').sub(/.atom\z/, '')
-  end
-
-  private
-
-  def relative_url_root
-    if defined?(Gitlab::Application.config.relative_url_root)
-      Gitlab::Application.config.relative_url_root
-    end
-  end
-end
diff --git a/lib/constraints/group_url_constrainer.rb b/lib/constraints/group_url_constrainer.rb
index 2af6e1a11c8..5711d96a586 100644
--- a/lib/constraints/group_url_constrainer.rb
+++ b/lib/constraints/group_url_constrainer.rb
@@ -1,15 +1,17 @@
-require_relative 'constrainer_helper'
-
 class GroupUrlConstrainer
-  include ConstrainerHelper
-
   def matches?(request)
-    id = extract_resource_path(request.path)
+    id = request.params[:id]
+
+    return false unless valid?(id)
+
+    Group.find_by(path: id).present?
+  end
+
+  private
 
-    if id =~ Gitlab::Regex.namespace_regex
-      Group.find_by(path: id).present?
-    else
-      false
+  def valid?(id)
+    id.split('/').all? do |namespace|
+      NamespaceValidator.valid?(namespace)
     end
   end
 end
diff --git a/lib/constraints/project_url_constrainer.rb b/lib/constraints/project_url_constrainer.rb
new file mode 100644
index 00000000000..730b05bed97
--- /dev/null
+++ b/lib/constraints/project_url_constrainer.rb
@@ -0,0 +1,13 @@
+class ProjectUrlConstrainer
+  def matches?(request)
+    namespace_path = request.params[:namespace_id]
+    project_path = request.params[:project_id] || request.params[:id]
+    full_path = namespace_path + '/' + project_path
+
+    unless ProjectPathValidator.valid?(project_path)
+      return false
+    end
+
+    Project.find_with_namespace(full_path).present?
+  end
+end
diff --git a/lib/constraints/user_url_constrainer.rb b/lib/constraints/user_url_constrainer.rb
index 4d722ad5af2..9ab5bcb12ff 100644
--- a/lib/constraints/user_url_constrainer.rb
+++ b/lib/constraints/user_url_constrainer.rb
@@ -1,15 +1,5 @@
-require_relative 'constrainer_helper'
-
 class UserUrlConstrainer
-  include ConstrainerHelper
-
   def matches?(request)
-    id = extract_resource_path(request.path)
-
-    if id =~ Gitlab::Regex.namespace_regex
-      User.find_by('lower(username) = ?', id.downcase).present?
-    else
-      false
-    end
+    User.find_by_username(request.params[:username]).present?
   end
 end
diff --git a/lib/gitlab/regex.rb b/lib/gitlab/regex.rb
index c12358ceef4..a06cf6a989c 100644
--- a/lib/gitlab/regex.rb
+++ b/lib/gitlab/regex.rb
@@ -8,8 +8,10 @@ module Gitlab
     # allow non-regex validatiions, etc), `NAMESPACE_REGEX_STR_SIMPLE` serves as a Javascript-compatible version of
     # `NAMESPACE_REGEX_STR`, with the negative lookbehind assertion removed. This means that the client-side validation
     # will pass for usernames ending in `.atom` and `.git`, but will be caught by the server-side validation.
-    NAMESPACE_REGEX_STR_SIMPLE = '[a-zA-Z0-9_\.][a-zA-Z0-9_\-\.]*[a-zA-Z0-9_\-]|[a-zA-Z0-9_]'.freeze
+    PATH_REGEX_STR = '[a-zA-Z0-9_\.][a-zA-Z0-9_\-\.]*'.freeze
+    NAMESPACE_REGEX_STR_SIMPLE = PATH_REGEX_STR + '[a-zA-Z0-9_\-]|[a-zA-Z0-9_]'.freeze
     NAMESPACE_REGEX_STR = '(?:' + NAMESPACE_REGEX_STR_SIMPLE + ')(?<!\.git|\.atom)'.freeze
+    PROJECT_REGEX_STR = PATH_REGEX_STR + '(?<!\.git|\.atom)'.freeze
 
     def namespace_regex
       @namespace_regex ||= /\A#{NAMESPACE_REGEX_STR}\z/.freeze
@@ -42,7 +44,15 @@ module Gitlab
     end
 
     def project_path_regex
-      @project_path_regex ||= /\A[a-zA-Z0-9_.][a-zA-Z0-9_\-\.]*(?<!\.git|\.atom)\z/.freeze
+      @project_path_regex ||= /\A#{PROJECT_REGEX_STR}\z/.freeze
+    end
+
+    def project_route_regex
+      @project_route_regex ||= /#{PROJECT_REGEX_STR}/.freeze
+    end
+
+    def project_git_route_regex
+      @project_route_git_regex ||= /#{PATH_REGEX_STR}\.git/.freeze
     end
 
     def project_path_regex_message