Drush sql-create --db-su doesn't work with empty root passwords

gistfile1.txt

The crux is drush doesn't pick up the super user from the CLI, using --db-su, unless there is a ~/.my.cnf
nor does it pick it up from the alias file at all.

My environment is a Mac with Mountain Lion MYSQL install using Homebrew

mysql --version:
Ver 14.14 Distrib 5.6.19, for osx10.9 (x86_64)

php --version
PHP 5.4.30 (cli) (built: Jul 29 2014 23:43:29)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies

drush --version
 Drush Version   :  7.0-dev
 lstest commit: 763fad5316607f09c6321584f2831efd120a5b19  (something after 7.0.0-alpha7)
Alias file:

<?php

$aliases['test'] = array(
  'uri' => 'http://localhost/test.local',
  'root' => '/var/www/test',
  'databases' => array(
    'default' => array(
      'default' => array(
        'driver' => mysql,
        'username' => 'test_user',
        'password' => 'test_pass',
        'port' => 3306,
        'host' => localhost,
        'database' => testdb,
      ),
    ),
  ),
);

$drush sa @test --with-db

RESULT:
$aliases["test"] = array (
  'uri' => 'http://localhost/test.local',
  'root' => '/var/www/test',
  'databases' =>
  array (
    'default' =>
    array (
      'default' =>
      array (
        'driver' => 'mysql',
        'username' => 'test_user',
        'password' => 'test_pass',
        'port' => 3306,
        'host' => 'localhost',
        'database' => 'testdb',
      ),
    ),
  ),
  '#file' => '/Users/jdtaylor/.drush/test.aliases.drushrc.php',
  '#name' => 'test',
);

cmd$ drush @test sql-create -y -v -d

RESULT:
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.48 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.48 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [0.54 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [0.54 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [0.54 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [0.54 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; [0.98 sec, 5.82 MB]                                                                   [status]
Executing: mysql --defaults-extra-file=/private/tmp/drush_cksvsn --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_I8ZVfN
  ERROR 1045 (28000): Access denied for user 'test_user'@'localhost' (using password: YES)
Returned from hook drush_sql_create [1.13 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [1.13 sec, 5.79 MB]

cmd$  drush @test sql-create -y -v -d --db-su=root

RESULT:
Starting Drush preflight. [0.01 sec, 1.9 MB]                                                                                                                                                    [preflight]
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.91 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.92 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [1.14 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [1.14 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [1.14 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [1.14 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; GRANT ALL PRIVILEGES ON testdb.* TO 'test_user'@'localhost' IDENTIFIED BY 'test_pass';[status]
FLUSH PRIVILEGES; [1.17 sec, 5.82 MB]
Executing: mysql --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_TE5O5H
  ERROR 1044 (42000) at line 1: Access denied for user ''@'localhost' to database 'testdb'
Returned from hook drush_sql_create [1.23 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [1.23 sec, 5.79 MB]

alias file:
<?php

$aliases['test'] = array(
  'db-su' => 'root',
  'db-su-pw' => '',
  'uri' => 'http://localhost/test.local',
  'root' => '/var/www/test',
  'databases' => array(
    'default' => array(
      'default' => array(
        'driver' => mysql,
        'username' => 'test_user',
        'password' => 'test_pass',
        'port' => 3306,
        'host' => localhost,
        'database' => testdb,
      ),
    ),
  ),
);

cmd: drush @test sql-create -y -v -d

RESULT:
Starting Drush preflight. [0.01 sec, 1.9 MB]                                                                                                                                                    [preflight]
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.47 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.47 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [0.52 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [0.52 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [0.52 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [0.52 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; GRANT ALL PRIVILEGES ON testdb.* TO 'test_user'@'localhost' IDENTIFIED BY 'test_pass';[status]
FLUSH PRIVILEGES; [0.53 sec, 5.82 MB]
Executing: mysql --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_YT2rHB
  ERROR 1044 (42000) at line 1: Access denied for user ''@'localhost' to database 'testdb'
Returned from hook drush_sql_create [0.54 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [0.54 sec, 5.79 MB]


With ~/.my.cnf:

[mysql]
user = root
password =

[client]
user = root
password =

Alias File:
<?php

$aliases['test'] = array(
  'uri' => 'http://localhost/test.local',
  'root' => '/var/www/test',
  'databases' => array(
    'default' => array(
      'default' => array(
        'driver' => mysql,
        'username' => 'test_user',
        'password' => 'test_pass',
        'port' => 3306,
        'host' => localhost,
        'database' => testdb,
      ),
    ),
  ),
);

cmd: drush @test sql-create -y -v -d

RESULT:
Starting Drush preflight. [0.01 sec, 1.9 MB]                                                                                                                                                    [preflight]
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.47 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.48 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [0.53 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [0.53 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [0.53 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [0.53 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; [0.54 sec, 5.82 MB]                                                                   [status]
Executing: mysql --defaults-extra-file=/private/tmp/drush_g4Ch1f --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_ib72Xu
Returned from hook drush_sql_create [0.94 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [0.94 sec, 5.79 MB]

cmd: drush @test sql-create -y -v -d --db-su=root

RESULT:
Starting Drush preflight. [0.01 sec, 1.9 MB]                                                                                                                                                    [preflight]
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.48 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.49 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [0.54 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [0.54 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [0.54 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [0.54 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; GRANT ALL PRIVILEGES ON testdb.* TO 'test_user'@'localhost' IDENTIFIED BY 'test_pass';[status]
FLUSH PRIVILEGES; [0.54 sec, 5.82 MB]
Executing: mysql --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_it8bfU
Returned from hook drush_sql_create [0.58 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [0.58 sec, 5.79 MB]

alias file:
<?php

$aliases['test'] = array(
  'db-su' => 'root',
  'db-su-pw' => '',
  'uri' => 'http://localhost/test.local',
  'root' => '/var/www/test',
  'databases' => array(
    'default' => array(
      'default' => array(
        'driver' => mysql,
        'username' => 'test_user',
        'password' => 'test_pass',
        'port' => 3306,
        'host' => localhost,
        'database' => testdb,
      ),
    ),
  ),
);

cmd: drush @test sql-create -y -v -d --db-su=root

RESULT:
Starting Drush preflight. [0.01 sec, 1.9 MB]                                                                                                                                                    [preflight]
Loaded alias @test from file /Users/jdtaylor/.drush/test.aliases.drushrc.php [0.47 sec, 1.91 MB]                                                                                                   [notice]
Cache HIT cid: 7.0-dev-commandfiles-0-c36ec6c9d3c715f83d414d8ba6f2e918 [0.48 sec, 1.97 MB]                                                                                                          [debug]
Bootstrap to phase 0. [0.53 sec, 5.69 MB]                                                                                                                                                       [bootstrap]
Bootstrap to phase 0. [0.53 sec, 5.7 MB]                                                                                                                                                        [bootstrap]
Found command: sql-create (commandfile=sql) [0.53 sec, 5.7 MB]                                                                                                                                  [bootstrap]
Calling hook drush_sql_create [0.53 sec, 5.74 MB]                                                                                                                                                   [debug]
Creating database testdb. Any possible existing database will be dropped!
Do you really want to continue? (y/n): y
sql-query: DROP DATABASE IF EXISTS testdb; CREATE DATABASE testdb /*!40100 DEFAULT CHARACTER SET utf8 */; GRANT ALL PRIVILEGES ON testdb.* TO 'test_user'@'localhost' IDENTIFIED BY 'test_pass';[status]
FLUSH PRIVILEGES; [0.54 sec, 5.82 MB]
Executing: mysql --database=information_schema --host=localhost --port=3306 --silent  < /private/tmp/drush_UlZHrK
Returned from hook drush_sql_create [0.55 sec, 5.82 MB]                                                                                                                                             [debug]
Command dispatch complete [0.55 sec, 5.8 MB]