Fix failing test caused by a bad merge.

lib/persistence.js

@@ -20,15 +20,13 @@ function persist(modelfunc, keyfield)
 	if (!modelfunc.prototype.__properties && !modelfunc.prototype.serialize)
 		throw(new Error('persist only accepts polyclay models'));
 
-	if (!keyfield)
-		keyfield = '_id';
-
-	modelfunc.prototype.keyfield = keyfield;
-
 	// We must supply either a keyfield parameter or already have a 'key' property.
 	var keyprop = Object.getOwnPropertyDescriptor(modelfunc.prototype, 'key');
 	if (!keyprop)
 	{
+		if (!keyfield)
+			keyfield = '_id';
+
 		Object.defineProperty(modelfunc.prototype, 'key',
 		{
 			get: function getKey()
@@ -45,6 +43,8 @@ function persist(modelfunc, keyfield)
 	else
 		keyfield = 'key';
 
+	modelfunc.prototype.keyfield = keyfield;
+
 	_.assign(modelfunc, persist.statics);
 	_.assign(modelfunc.prototype, persist.plugins);
 }