From 9f523539ad96d1c1a3bb9e19d2a16e1db177f70b Mon Sep 17 00:00:00 2001
From: Krekoten' Marjan <krekoten@gmail.com>
Date: Sun, 19 Sep 2010 22:57:44 +0300
Subject: [PATCH] Ensure that mysql2 gem with mysql gem compatibility used. Fix uninitialized constant Mysql2 [#5502 state:resolved]

---
 Gemfile                                            |    2 +-
 .../lib/active_record/railties/databases.rake      |    2 +-
 .../rails/generators/rails/app/app_generator.rb    |    6 ++++++
 .../rails/generators/rails/app/templates/Gemfile   |    2 +-
 railties/test/generators/app_generator_test.rb     |    2 +-
 5 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Gemfile b/Gemfile
index d9f089f..9d29c42 100644
--- a/Gemfile
+++ b/Gemfile
@@ -45,7 +45,7 @@ platforms :ruby do
   group :db do
     gem "pg", ">= 0.9.0"
     gem "mysql", ">= 2.8.1"
-    gem "mysql2", ">= 0.2.3"
+    gem "mysql2", ">= 0.2.4"
   end
 end
 
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 3c5981a..ba369a9 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -83,7 +83,7 @@ namespace :db do
         @charset   = ENV['CHARSET']   || 'utf8'
         @collation = ENV['COLLATION'] || 'utf8_unicode_ci'
         creation_options = {:charset => (config['charset'] || @charset), :collation => (config['collation'] || @collation)}
-        error_class = config['adapter'] =~ /mysql2/ ? Mysql2::Error : Mysql::Error
+        error_class = "#{config['adapter'].capitalize}::Error".constantize
         access_denied_error = 1045
         begin
           ActiveRecord::Base.establish_connection(config.merge('database' => nil))
diff --git a/railties/lib/rails/generators/rails/app/app_generator.rb b/railties/lib/rails/generators/rails/app/app_generator.rb
index cdff174..6a586f6 100644
--- a/railties/lib/rails/generators/rails/app/app_generator.rb
+++ b/railties/lib/rails/generators/rails/app/app_generator.rb
@@ -401,6 +401,12 @@ module Rails
         else options[:database]
         end
       end
+      
+      def version_for_database
+        case options[:database]
+        when "mysql" then ">= 0.2.4"
+        end
+      end
 
       def require_for_database
         case options[:database]
diff --git a/railties/lib/rails/generators/rails/app/templates/Gemfile b/railties/lib/rails/generators/rails/app/templates/Gemfile
index d553c09..e2d7f23 100644
--- a/railties/lib/rails/generators/rails/app/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/app/templates/Gemfile
@@ -14,7 +14,7 @@ gem 'rails', '<%= Rails::VERSION::STRING %>'
 <%- end -%>
 
 <% unless options[:skip_active_record] -%>
-gem '<%= gem_for_database %>'<% if require_for_database %>, :require => '<%= require_for_database %>'<% end %>
+gem '<%= gem_for_database %>'<%if version_for_database %>, '<%= version_for_database %>'<% end %><% if require_for_database %>, :require => '<%= require_for_database %>'<% end %>
 <% end -%>
 
 # Use unicorn as the web server
diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 9ce2308..34684cd 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -159,7 +159,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   def test_config_another_database
     run_generator([destination_root, "-d", "mysql"])
     assert_file "config/database.yml", /mysql/
-    assert_file "Gemfile", /^gem\s+["']mysql2["']$/
+    assert_file "Gemfile", /^gem\s+["']mysql2["'],\s+["']>=\s+0\.2\.4["']$/
   end
 
   def test_config_database_is_not_added_if_skip_active_record_is_given
-- 
1.7.2