fix(modeling/cmd): do not fail updating non-changed id

Closes #420

lib/features/modeling/cmd/UpdatePropertiesHandler.js

@@ -71,7 +71,7 @@ UpdatePropertiesHandler.prototype.execute = function(context) {
       properties = context.properties,
       oldProperties = context.oldProperties || getProperties(businessObject, keys(properties));
 
-  if (ID in properties) {
+  if (isIdChange(properties, businessObject)) {
     ids.unclaim(businessObject[ID]);
 
     elementRegistry.updateId(element, properties[ID]);
@@ -126,7 +126,7 @@ UpdatePropertiesHandler.prototype.revert = function(context) {
   // update properties
   setProperties(businessObject, oldProperties);
 
-  if (ID in properties) {
+  if (isIdChange(properties, businessObject)) {
     ids.unclaim(properties[ID]);
 
     elementRegistry.updateId(element, oldProperties[ID]);
@@ -134,3 +134,8 @@ UpdatePropertiesHandler.prototype.revert = function(context) {
 
   return context.changed;
 };
+
+
+function isIdChange(properties, businessObject) {
+  return ID in properties && properties[ID] !== businessObject[ID];
+}

test/spec/features/modeling/UpdatePropertiesSpec.js

@@ -334,4 +334,24 @@ describe('features/modeling - update properties', function() {
 
   });
 
+
+  describe('error handling', function() {
+
+    it('should ignore unchanged id', inject(function(elementRegistry, modeling) {
+
+      // given
+      var flowConnection = elementRegistry.get('SequenceFlow_1');
+      var ids = flowConnection.businessObject.$model.ids;
+
+      // when
+      modeling.updateProperties(flowConnection, { id: 'SequenceFlow_1' });
+
+      // then
+      expect(ids.assigned('SequenceFlow_1')).to.exist;
+
+      expect(flowConnection.businessObject.id).to.equal('SequenceFlow_1');
+    }));
+
+  });
+
 });