PDF restricted to single page in Letter when using body height: 100%

[michaellisitsa]

Going from v60.2 to v61, there is an issue with content being cut off at one page. It appears to be related to minor rounding errors in the "Letter" page size that causes the below newly added code to falsely think the content is overflowing.

I have made a replit here
https://replit.com/@mlisitsa/Python-Weasyprint-Bug-Print-Cut-to-Single-Page#script.py

The issue occurs when you have body {height: 100%} and @page {size: letter, margin: 15mm}.

The offending code looks to be bc97131, where the resume_at gets set to None, even though there is more content in the body tag.

WeasyPrint/weasyprint/layout/block.py

Lines 743 to 750 in 1ac1594

	elif stop:
	if box.height != 'auto':
	if position_y > box.position_y + box.height:
	# Box heigh is fixed and it doesn’t overflow page, forget
	# overflowing children.
	resume_at = None
	adjoining_margins = []
	break

The resume_at then gets returned eventually to the make_page function

https://github.com/Kozea/WeasyPrint/blob/1ac1594cf3fe326ff09c4035d158b65fdc684b71/weasyprint/layout/page.py#L645-650

When I debugged it with Letter, you have the calculated position_y is approximately equal but ever so slightly bigger.

box.position_y + box.height
>> 999.3070866141732

position_y
>> 999.3070866141733

When using A4 page size, they are the same, and content prints correctly over multiple pages

position_y
>> 1065.8267716535433
box.position_y + box.height
>> 1065.8267716535433

[liZe]

Hi!

Thanks for reporting this issue. A lot of rounding errors have been fixed in the past to detect overflow on pages, that’s another case we have to handle.