Merge branch 'auth_hash_fix' into 'master'

Expand character set of usernames created by Omniauth

When a user is created by Omniauth, Gitlab tries to assign the username based on the information provided in the auth hash. If no nickname is present, it uses the part of the email address before the @. This portion of the email address is run through the `parameterize` method, presumably to convert Unicode characters to ASCII.

`parameterize` strips out a number of characters that are valid in usernames. For example, `john.doe` is a valid Gitlab username, but parameterize will turn this into `john-doe`.

Instead of `parameterize`, this merge request uses `normalize` to convert non-ascii characters. This allows all acceptable characters to be used when creating a username from an email address. 

See merge request !660

lib/gitlab/o_auth/auth_hash.rb

@@ -62,7 +62,7 @@ module Gitlab
       # Get the first part of the email address (before @)
       # In addtion in removes illegal characters
       def generate_username(email)
-        email.match(/^[^@]*/)[0].parameterize
+        email.match(/^[^@]*/)[0].mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/,'').to_s
       end
 
       def generate_temporarily_email(username)

spec/lib/gitlab/o_auth/auth_hash_spec.rb

@@ -14,7 +14,7 @@ describe Gitlab::OAuth::AuthHash, lib: true do
   let(:uid_raw) do
     "CN=Onur K\xC3\xBC\xC3\xA7\xC3\xBCk,OU=Test,DC=example,DC=net"
   end
-  let(:email_raw) { "onur.k\xC3\xBC\xC3\xA7\xC3\xBCk@example.net" }
+  let(:email_raw) { "onur.k\xC3\xBC\xC3\xA7\xC3\xBCk_ABC-123@example.net" }
   let(:nickname_raw) { "ok\xC3\xBC\xC3\xA7\xC3\xBCk" }
   let(:first_name_raw) { 'Onur' }
   let(:last_name_raw) { "K\xC3\xBC\xC3\xA7\xC3\xBCk" }
@@ -66,7 +66,7 @@ describe Gitlab::OAuth::AuthHash, lib: true do
     before { info_hash.delete(:nickname) }
 
     it 'takes the first part of the email as username' do
-      expect(auth_hash.username).to eql 'onur-kucuk'
+      expect(auth_hash.username).to eql 'onur.kucuk_ABC-123'
     end
   end