Copy the contents of Simple.html to Aliens.html and press 'Get diff'. After 12 seconds an exception is thrown.
|mediawiki/extensions/VisualEditor : master||Update VE core submodule to master (e5dffec)|
|VisualEditor/VisualEditor : master||Detect node type/attribute changes in the visual diff|
|VisualEditor/VisualEditor : master||Record no diff if linear diff length is zero|
This was caused by deciding a content branch node with content length 0 was modified to an alien node.
A diff is recorded if the ratio of retained content to changed content is above a threshold. Here both were zero, so above the threshold, but it should not be interpreted as a modification.