Affected versions

• Firefox 84.0b8 (BuildId:20201203211213) - print.tab_modal.enabled pref is disabled by default on b8
• Firefox 85.0a1 (BuildId:20201206213246)

Affected platforms

• Windows 10 64bit
• macOS 10.15
• Ubuntu 20.04 64bit.

Steps to reproduce

1. Launch Firefox.
2. Access any random website (example)
3. Hit Ctrl + P in order to open the print preview.
4. Select the “Custom” option from the Pages section.
5. Set the value of 10 inside the Scale field.
6. Select the “All” option from the Pages section.
7. Click the “Fit to page width” radio button from the Scale section.

Expected result

• The sheets of paper value & the print preview gets updated displaying all the available pages.

Actual result

• The sheets of paper value & the print preview doesn’t get updated.

Regression Range

• This seems to be a regression:
• Pushlog
• Potential regressor: Bug 1669854

Notes

• For further information please observe the attached screencast.
• The actual print job is also affected by this issue.
• [Suggested Severity] I think that S3 fits for this issue.

Hi Emilio!

It seems that mozregression pointed out Bug 1669854 for causing this regression.

Can you please take a look?

Thank you!

With the patch from Bug 499640 applied, this problem is no longer reproducible. I think we can hold off on a fix for this because that patch should land soon

Ah, sweet Emma, thanks you!

Bug 499640 is on Nightly now and I can no longer reproduce

This issue is verified fixed using Firefox 85.0b2 (BuildId:20201215185920) and Firefox 86.0a1 (BuildId:20201217092748) on Windows 10 64bit, macOS 10.13 & Ubuntu 20.04.