Camelia Badau [:cbadau], Desktop QA Reporter
	Description • 6 years ago

[Affected versions]:
- latest Nightly 59.0a1 (2018-01-12)
- Firefox 58 Beta 16
- Firefox 54.0.1
- Firefox 56 Beta 3

[Affected platforms]:
- Windows 10 x64
- Windows 8.1 x64
- macOS 10.12
- Ubuntu 14.04 x64


[Steps to reproduce]:
1. Open a pdf page (e.g: http://www.dbsparks.com/research/html/SNRN02.pdf , http://www23.statcan.gc.ca/imdb-bmdi/pub/instrument/3901_Q2_V3-eng.pdf).
2. Select "Print Preview"(on Windows)/"Open PDF in Preview" (on Mac).  
3. Choose "Landscape". 

[Expected result]:
- The page is correctly displayed in Print Preview while in Landscape.

[Actual result]:
- The page is cut off in Print Preview while in Landscape. Please see attachment "issue.png". 

[Regression range]:
- Since the issue is reproducible on Firefox 54.0.1 is not a recent regression. I will come back ASAP with the regression range.

	Jonathan Watt [:jwatt]
	Comment 1 • 6 years ago

So you're trying to print portrait pages to landscape paper. That seems like a weird use case but other browsers do handle it better than we do.

This is somewhat expected given your settings (the default admittedly) as shown in your screenshot. The Scale field is set to "Shrink to Fit", which means fit the width of the content to be printed to the width of the print page (see bug 188365 for renaming this "Shrink to fit page width"). For portrait PDF pages that setting scales their width up to fit the width of the landscape paper...and naturally we then truncate the bottom of the PDF pages.

The user can "fix" this somewhat by trying out different values in the Scale field until the page fits better. That's annoying though, both because it requires manual tweaking, and because in the end it still doesn't look great since the PDF page is positioned at the top-left of the sheet.

	Jonathan Watt [:jwatt]
	Comment 2 • 6 years ago

We could make things a lot better by doing two things:

 - Having two scaling settings: "Fit to page width" and "Fit to page
   height", and select a sensible default based on the orientation
   of the PDF pages that are being printed.

 - Having the PDF pages centered in the print pages when they have
   to be scaled to fit.

This requires both UI and layout work.