Previewing a page and then saving it without further modifications should result in one serialization request being made to Parsoid, not two. The serialized DOM generated in course of responding to the preview request should be re-used when saving whenever VisualEditor can determine that no modifications intervene these two operations.

Version: unspecified
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=56011