Imagine this scenario:
- User creates app\design\frontend\default\mytheme\template\checkout\cart.phtml
- User updates from 1.7.0 to 1.8.1
- Cart page item qty updating does not work
- User compares both base template file and his theme template file, finds out it's missing the new line
<?php echo $this->getBlockHtml('formkey'); ?>
The process above has to be repeated for every template file that the theme overrides.
Is there a better workflow for theming magento?