Merge pull request #9493 from kennyj/fix_wrong_exception

Wrong exception is occured when raising no translatable exception

Closes #8617

activerecord/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*   Fix a problem wrong exception is occured
+    when raising no translatable exception in PostgreSQL. 
+
+    *kennyj*
+
 *   Support PostgreSQL specific column types when using `change_table`.
     Fixes #9480.
 

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -675,6 +675,8 @@ def postgresql_version
         UNIQUE_VIOLATION      = "23505"
 
         def translate_exception(exception, message)
+          return exception unless exception.respond_to?(:result)
+
           case exception.result.try(:error_field, PGresult::PG_DIAG_SQLSTATE)
           when UNIQUE_VIOLATION
             RecordNotUnique.new(message, exception)

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -250,6 +250,12 @@ def test_distinct_with_nulls
         assert_equal "DISTINCT posts.title, posts.updater_id AS alias_0", @connection.distinct("posts.title", ["posts.updater_id desc nulls last"])
       end
 
+      def test_raise_error_when_cannot_translate_exception
+        assert_raise TypeError do
+          @connection.send(:log, nil) { @connection.execute(nil) }
+        end
+      end
+
       private
       def insert(ctx, data)
         binds   = data.map { |name, value|