Add environment variable RAILS_DEFAULT_DATABASE, which allows the builtin...

Add environment variable RAILS_DEFAULT_DATABASE, which allows the builtin default of 'mysql' to be overridden.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6429 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/CHANGELOG

 *SVN*
 
+* Add environment variable RAILS_DEFAULT_DATABASE, which allows the builtin default of 'mysql' to be overridden. [Nicholas Seckar]
+
 * Windows: include MinGW in RUBY_PLATFORM check.  #2982 [okkez000@gmail.com, Kaspar Schiess]
 
 * Split out the basic plugin locator functionality into an abstract super class. Add a FileSystemLocator to do the job of checking the plugin_paths for plugins. Add plugin_locators configuration option which will iterate over the set of plugin locators and load each of the plugin loaders they return. Rename locater everywhere to locator. [Marcel Molina Jr.] 

railties/lib/rails_generator/generators/applications/app/app_generator.rb

@@ -7,7 +7,8 @@ class AppGenerator < Rails::Generator::Base
 
   DATABASES = %w(mysql oracle postgresql sqlite2 sqlite3 frontbase)
 
-  default_options   :db => "mysql", :shebang => DEFAULT_SHEBANG, :freeze => false
+  default_options   :db => (ENV["RAILS_DEFAULT_DATABASE"] || "mysql"),
+    :shebang => DEFAULT_SHEBANG, :freeze => false
   mandatory_options :source => "#{File.dirname(__FILE__)}/../../../../.."
 
   def initialize(runtime_args, runtime_options = {})