closes #6340

src/database/mongo/main.js

@@ -66,7 +66,21 @@ module.exports = function (db, module) {
 		if (!key) {
 			return callback();
 		}
-		module.getObjectField(key, 'data', callback);
+		module.getObject(key, function (err, objectData) {
+			if (err) {
+				return callback(err);
+			}
+			// fallback to old field name 'value' for backwards compatibility #6340
+			var value = null;
+			if (objectData) {
+				if (objectData.hasOwnProperty('data')) {
+					value = objectData.data;
+				} else if (objectData.hasOwnProperty('value')) {
+					value = objectData.value;
+				}
+			}
+			callback(null, value);
+		});
 	};
 
 	module.set = function (key, value, callback) {

test/database/keys.js

@@ -27,6 +27,14 @@ describe('Key methods', function () {
 		});
 	});
 
+	it('should return null if key does not exist', function (done) {
+		db.get('doesnotexist', function (err, value) {
+			assert.ifError(err);
+			assert.equal(value, null);
+			done();
+		});
+	});
+
 	it('should return true if key exist', function (done) {
 		db.exists('testKey', function (err, exists) {
 			assert.ifError(err);