commit 6aeeb605981c45654adf40c79aaf1327e5709982
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Tue Aug 2 16:46:36 2011 -0700

    prevent sql injection attacks by escaping quotes in column names

diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 6f41f84..c50022b 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -238,7 +238,7 @@ module ActiveRecord
       end
 
       def quote_column_name(name) #:nodoc:
-        @quoted_column_names[name] ||= "`#{name}`"
+        @quoted_column_names[name] ||= "`#{name.to_s.gsub('`', '``')}`"
       end
 
       def quote_table_name(name) #:nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 1616698..242f3f7 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -162,7 +162,7 @@ module ActiveRecord
       end
 
       def quote_column_name(name) #:nodoc:
-        %Q("#{name}")
+        %Q("#{name.to_s.gsub('"', '""')}")
       end
 
 
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index e9af77c..242be2a 100755
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -79,6 +79,23 @@ end
 class BasicsTest < ActiveRecord::TestCase
   fixtures :topics, :companies, :developers, :projects, :computers, :accounts, :minimalistics, 'warehouse-things', :authors, :categorizations, :categories, :posts
 
+  def test_column_names_are_escaped
+    conn      = ActiveRecord::Base.connection
+    classname = conn.class.name[/[^:]*$/]
+    badchar   = {
+      'SQLite3Adapter'    => '"',
+      'MysqlAdapter'      => '`',
+      'Mysql2Adapter'     => '`',
+      'PostgreSQLAdapter' => '"',
+      'OracleAdapter'     => '"',
+    }.fetch(classname) {
+      raise "need a bad char for #{classname}"
+    }
+
+    quoted = conn.quote_column_name "foo#{badchar}bar"
+    assert_equal("#{badchar}foo#{badchar * 2}bar#{badchar}", quoted)
+  end
+
   def test_table_exists
     assert !NonExistentTable.table_exists?
     assert Topic.table_exists?