Revert "Revert disallowing usernames to end in period."

This reverts commit c75c6b84.

CHANGELOG

@@ -97,6 +97,7 @@ v 7.10.0 (unreleased)
   - Fix admin user projects lists.
   - Don't leak private group existence by redirecting from namespace controller to group controller.
   - Ability to skip some items from backup (database, respositories or uploads)
+  - Fix "Hello @username." references not working by no longer allowing usernames to end in period.
   - Archive repositories in background worker.
   - Import GitHub, Bitbucket or GitLab.com projects owned by authenticated user into current namespace.
   - Project labels are now available over the API under the "tag_list" field (Cristian Medina) 

db/migrate/20150324133047_remove_periods_at_ends_of_usernames.rb

+class RemovePeriodsAtEndsOfUsernames < ActiveRecord::Migration
+  include Gitlab::ShellAdapter
+
+  class Namespace < ActiveRecord::Base
+    class << self
+      def find_by_path_or_name(path)
+        find_by("lower(path) = :path OR lower(name) = :path", path: path.downcase)
+      end
+
+      def clean_path(path)
+        path = path.dup
+        path.gsub!(/@.*\z/,             "")
+        path.gsub!(/\.git\z/,           "")
+        path.gsub!(/\A-+/,              "")
+        path.gsub!(/\.+\z/,             "")
+        path.gsub!(/[^a-zA-Z0-9_\-\.]/, "")
+
+        counter = 0
+        base = path
+        while Namespace.find_by_path_or_name(path)
+          counter += 1
+          path = "#{base}#{counter}"
+        end
+
+        path
+      end
+    end
+  end
+
+  def up
+    changed_paths = {}
+
+    select_all("SELECT id, username FROM users WHERE username LIKE '%.'").each do |user|
+      username_was = user["username"]
+      username = Namespace.clean_path(username_was)
+      changed_paths[username_was] = username
+
+      username = quote_string(username)
+      execute "UPDATE users SET username = '#{username}' WHERE id = #{user["id"]}"
+      execute "UPDATE namespaces SET path = '#{username}', name = '#{username}' WHERE type IS NULL AND owner_id = #{user["id"]}"
+    end
+
+    select_all("SELECT id, path FROM namespaces WHERE type = 'Group' AND path LIKE '%.'").each do |group|
+      path_was = group["path"]
+      path = Namespace.clean_path(path_was)
+      changed_paths[path_was] = path
+
+      path = quote_string(path)
+      execute "UPDATE namespaces SET path = '#{path}' WHERE id = #{group["id"]}"
+    end
+
+    changed_paths.each do |path_was, path|
+      if gitlab_shell.mv_namespace(path_was, path)
+        # If repositories moved successfully we need to remove old satellites
+        # and send update instructions to users.
+        # However we cannot allow rollback since we moved namespace dir
+        # So we basically we mute exceptions in next actions
+        begin
+          gitlab_shell.rm_satellites(path_was)
+          # We cannot send update instructions since models and mailers
+          # can't safely be used from migrations as they may be written for 
+          # later versions of the database.
+          # send_update_instructions
+        rescue
+          # Returning false does not rollback after_* transaction but gives
+          # us information about failing some of tasks
+          false
+        end
+      else
+        # if we cannot move namespace directory we should rollback
+        # db changes in order to prevent out of sync between db and fs
+        raise Exception.new('namespace directory cannot be moved')
+      end
+    end
+  end
+end

lib/gitlab/regex.rb

@@ -2,7 +2,7 @@ module Gitlab
   module Regex
     extend self
 
-    NAMESPACE_REGEX_STR = '(?:[a-zA-Z0-9_\.][a-zA-Z0-9_\-\.]*)'.freeze
+    NAMESPACE_REGEX_STR = '(?:[a-zA-Z0-9_\.][a-zA-Z0-9_\-\.]*[a-zA-Z0-9_\-]|[a-zA-Z0-9_])'.freeze
 
     def namespace_regex
       @namespace_regex ||= /\A#{NAMESPACE_REGEX_STR}\z/.freeze
@@ -10,7 +10,7 @@ module Gitlab
 
     def namespace_regex_message
       "can contain only letters, digits, '_', '-' and '.'. " \
-      "Cannot start with '-'." \
+      "Cannot start with '-' or end in '.'." \
     end