Fixed #1413.

app/models/CocoModel.coffee

@@ -220,6 +220,9 @@ class CocoModel extends Backbone.Model
     catch error
       console.error 'Error applying delta\n', JSON.stringify(delta, null, '\t'), '\n\nto attributes\n\n', newAttributes
       return false
+    for key, value of newAttributes
+      delete newAttributes[key] if _.isEqual value, @attributes[key]
+      
     @set newAttributes
     return true
 

test/app/views/editor/PatchModal.spec.coffee

@@ -0,0 +1,19 @@
+LevelComponent = require 'models/LevelComponent'
+Patch = require 'models/Patch'
+
+PatchModal = require 'views/editor/PatchModal'
+
+describe 'PatchModal', ->
+  describe 'acceptPatch', ->
+    it 'triggers LevelComponents and Systems to recompile their code', ->
+      levelComponent = new LevelComponent({ code: 'newList = (item.prop for item in list)', id: 'id' })
+      levelComponent.markToRevert()
+      levelComponent.set('code', 'func = -> console.log()')
+      patch = new Patch({delta: levelComponent.getDelta(), target: 'id'})
+
+      levelComponent = new LevelComponent({ code: 'newList = (item.prop for item in list)', id: 'id' })
+      levelComponent.markToRevert()
+      patchModal = new PatchModal(patch, levelComponent)
+      patchModal.render()
+      patchModal.acceptPatch()
+      expect(levelComponent.get('js').indexOf('function()')).toBeGreaterThan(-1)