mysqldump incorrectly reads the variable "database" as "databases"

Putting a "database=some_db" (where some_db is a valid database) under the [client] section of ~/.my.cnf (or any other config files parsed by mysqldump) will result on this warning on the execution of mysqldump, even if a database (or several) are specified for the dump :

$ mysqldump --help                                                                                                   

Warning: mysqldump: ignoring option '--databases' due to invalid value 'valid_db'

mysqldump  Ver 10.14 Distrib 5.5.40-MariaDB, for debian-linux-gnu (i686)

Copyright (c) 2000, 2014, Oracle, Monty Program Ab and others.

[...]

$ mysqldump valid_db                                                                                                

Warning: mysqldump: ignoring option '--databases' due to invalid value 'valid_db'

-- MySQL dump 10.14  Distrib 5.5.40-MariaDB, for debian-linux-gnu (i686)

--

-- Host: localhost    Database: valid_db

[...]

The same happens when running "mysqldump --databases some_db"

The error message is confusing as the specified database name is valid.

The upstream bug (http://bugs.mysql.com/bug.php?id=18209) has been reported almost a decade ago and a patch that added the specific option "database" to mysqldump has been provided on the bug report but never made it to the main tree : http://lists.mysql.com/commits/6311

Another solution would be to make simply that mysqldump doesnt read the database parameter from the config file which would be safe as it should have never worked before.