Spread.page_count — accessor returning the number of pages in a spread (1 = single, 2 = facing); it syncs the page records internally, so it is correct for both editor-created and loaded documents
Fixes
set_manifest_data now also accepts preserve_geometry inside the data object (the positional argument still wins). Previously it was only read as the second argument, so passing it in the data object was ignored and defaulted to true, leaving scale-to-fill images un-refreshed