Give a more informative error message instead of just raising a load error when mysql gem isn't installed

1 files changed, 8 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index cfd2402d9d..076b7f63c2 100755
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -58,7 +58,14 @@ module ActiveRecord
       end
 
       # Require the MySQL driver and define Mysql::Result.all_hashes
-      require_library_or_gem('mysql') unless defined? Mysql
+      unless defined? Mysql
+        begin
+          require_library_or_gem('mysql')
+        rescue LoadError
+          $stderr.puts '!!! The bundled mysql.rb driver has been removed from Rails 2.2. Please install the mysql gem and try again: gem install mysql.'
+          raise
+        end
+      end
       MysqlCompat.define_all_hashes_method!
 
       mysql = Mysql.init