Merge pull request #8057 from frodsan/fix_sqlite_mutate_arg

SQLite3Adapter#type_cast should not mutate arguments
Conflicts:
	activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

2 files changed, 9 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 731f7e2049..e80b465bab 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -205,7 +205,7 @@ module ActiveRecord
           value = super
           if column.type == :string && value.encoding == Encoding::ASCII_8BIT
             logger.error "Binary data inserted for `string` type on column `#{column.name}`" if logger
-            value.encode! 'utf-8'
+            value = value.encode Encoding::UTF_8
           end
           value
         end
diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
index 97b56d38d7..ec69a36174 100644
--- a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
@@ -164,6 +164,14 @@ module ActiveRecord
         end
       end
 
+      def test_type_cast_should_not_mutate_encoding
+        return skip('only test encoding on 1.9') unless "<3".encoding_aware?
+
+        name  = 'hello'.force_encoding(Encoding::ASCII_8BIT)
+        owner = Owner.create(:name => name)
+        assert_equal Encoding::ASCII_8BIT, name.encoding
+      end
+
       def test_execute
         @conn.execute "INSERT INTO items (number) VALUES (10)"
         records = @conn.execute "SELECT * FROM items"