Thank you mondrake for your review!
Here is an updated patch.
!is_null seems redundant here.
Done
better name this createFallbackImageFile(), 'mock' remind me of PHPUnit tests.
Done
drupal_get_path is deprecated and not present in D10
Done
It should be possible to configure which image file to use as a fallback.
Added the possibility to set a custom fallback image via the module settings page.\
I also added a simple test. Unfortunately had no chance to verify it.
Please check when you have a moment.
nick_nem → created an issue.
nick_nem → created an issue.