Affected versions

• Firefox 82.0b5
• Firefox 83.0a1

Affected platforms

• Windows 10
• macOS 10.13

Steps to reproduce

1. Launch Firefox
2. Access this test page containing vertical frames
3. Access Print preview and select "Save to PDF" option

Expected result

• The preview is rendered correctly

Actual result

• When selected, the preview pages zooms in and cuts off the writings in the page.

Regression range

• Seems that this is a fairly recent regression (~15 days),
• Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=a4dccb7df26ef69e7fe86d3fcaa79fde8082bc8a&tochange=d7d26615220c82cf6cba5e395a9c18558d6f0514.

Additional notes

• The issue can be seen in the attachment
• Ubuntu 20 doesn't seem to be affected

Suggested severity

• S3

Hi Catalin: Can you share what scale setting you were using in print preview? At 100% scale or scale-to-fit it should fit correctly, but at larger scale sizes some of the text may be cut off.

This happens for me on macOS in v83, v82 and v81 if I select A5 as the paper size (with 'Scale to page width' still selected). It happens both when print.tab_modal.enabled is set to true and when it is set to false. Is the difference you've seen in the last few days maybe due to settings changes, or testing with different profiles with different print settings saved to prefs?

We're probably not applying the 'Scale to page width' logic properly for <frameset> frames. I'm not sure we'll ever try to do that though, since <frameset> is extremely rarely used on the Web now and is not a priority for us at all. It's definitely not something we'll be trying to fix in v82.

Hi Sean, yeah this is on a clean profile, and using the default settings. And it seems that it uses A5 paper size by default