Steps to reproduce:

Open any PDF file (either online or local). Viewing works well. But when printing extra margins are added, visible in the new print preview.

Actual results:

The extra margins are not only visible in print preview, but they also print as shown in preview.

Expected results:

PDF file should print the way it is shown in the Firefox tab. Note: Thunderbird does not have that problem and uses the same print preview.

The Bugbug bot thinks this bug should belong to the 'Firefox::PDF Viewer' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Is this a regression or has it always behaved this way for you?
If it is a regression, could you try using mozregression to pinpoint the cause of this?

confirming with Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:100.0) Gecko/20100101 Firefox/99.0a1 Nightly Build: 20220221094019

It is not a regression.. it is reproducible back to 2013...

(In reply to Marco Castelluccio [:marco] from comment #2)

Is this a regression or has it always behaved this way for you?
If it is a regression, could you try using mozregression to pinpoint the cause of this?

For me, I believe that it showed up with release 97. It used to work as it should, especially before the new print dialog was added.

The original view is visible on the bottom half. Note the small margins left, right and bottom. The print preview window shows margins that are about twice as wide, and that is how the file prints. This was an email attachment, and if you print it from Thunderbird you get the small margins.

Kenan, I think what you're seeing is likely a different bug (can you file it separately?). In the case of snoopy42weg-bugzilla, the margins of the page are doubled.

snoopy42weg-bugzilla it would be great if you could use mozregression, it would give us a clear indication of when this started happening.

Another question, what version of Thunderbird are you using?

(In reply to Marco Castelluccio [:marco] from comment #8)

snoopy42weg-bugzilla it would be great if you could use mozregression, it would give us a clear indication of when this started happening.

Ok, I'll give that a try tomorrow. I have never used it, but found the instructions. I'll report back what I find.

Another question, what version of Thunderbird are you using?

It's version 91.6.1, and strangely it is reported as 32-bit even though I'm running 64-bit windows 10 .

:reporter, could you attach the pdf to bug please ?

as requested: original pdf file shown in print preview

I have the same problem, with firefox 100.0.1, on windows 11. Viewing the pdf is good but the printing preview is wrong. I have tried every parameter in about:config but nothing worked. I am forced to use an external application or other browser to print my pdfs.

It must be that most users don't print pdf files from Firefox. It is odd that nobody else mentions this bug, and it has not yet been fixed. Even though Thunderbird uses (apparently) the same pdf viewer as well as the print preview, but Thunderbird does not have this bug and prints pdf files correctly.

What are the page, the margin and scale settings in the printing dialog (under "More settings") ?

While trying to answer your question in detail, I stumbled across the resolution of the problem: the margin setting has to be set to "none" to print the document with the margins as you see it in the tab in Firefox. Any margin setting other than "zero" is used as an additional margin and shrinks the document in preview (and in print) even when the scale is set to 100%.

The print dialog in Thunderbird does NOT have a margin dialog under "more settings", hence the problem never shows up.

This should close out this "bug", which turns out to be a "feature"! Who closes out this bug?