[postgres] handle null values in array columns with AR < 4.0 (fixes #548)

Author: kares

src/java/arjdbc/postgresql/PostgreSQLRubyJdbcConnection.java

@@ -35,7 +35,6 @@
 import java.sql.Statement;
 import java.sql.Timestamp;
 import java.sql.Types;
-import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
@@ -463,7 +462,7 @@ protected IRubyObject arrayToRuby(final ThreadContext context,
         final Ruby runtime, final ResultSet resultSet, final int column)
         throws SQLException {
         if ( rawArrayType == Boolean.TRUE ) { // pre AR 4.0 compatibility
-            return runtime.newString( resultSet.getString(column) );
+            return stringToRuby(context, runtime, resultSet, column);
         }
         // NOTE: avoid `finally { array.free(); }` on PostgreSQL due :
         // java.sql.SQLFeatureNotSupportedException:

test/db/postgresql/array_compat_test.rb

@@ -15,7 +15,7 @@ def setup
     @connection.execute 'ALTER TABLE "pg_arrays" ADD COLUMN "bool_1d" boolean[]'
 
     @connection.execute "INSERT INTO \"pg_arrays\"(bool_1d, str_2d, int_1d) " <<
-      " VALUES ('{f, t, t}', '{{\"a\",\"b\"}, {\"c\",\"d\"}}', '{1, 2, 3}')"
+                        " VALUES ('{f, t, t}', '{{\"a\",\"b\"}, {\"c\",\"d\"}}', '{1, 2, 3}')"
   end
 
   def teardown
@@ -39,4 +39,11 @@ def test_column_values
     assert_equal "{f,t,t}", arr.bool_1d
   end
 
+  def test_null_column_values
+    arr = PgArray.create; arr.reload
+    assert_nil arr.str_2d
+    assert_equal '{}', arr.int_1d # default {}
+    assert_nil arr.bool_1d
+  end
+
 end if ActiveRecord::VERSION::MAJOR < 4