User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:70.0) Gecko/20100101 Firefox/70.0

Steps to reproduce:

I try to print a page.

Actual results:

The resulting Print doesn't contain the entire page. The Print Preview also doesn't show the entire page. This is bugging me for years, I always have to use Chrome when I want to print something.

Expected results:

The entire page should have been printed.

Check "firefoxPrint - https://www.doomworld.com/forum/topic/68477-hocusdoom-released-in-idgames/?tab=comments#comment-1265795" for comparison.

Check "firefoxPrint - https://www.reddit.com/r/tifu/comments/ebq476/tifu_by_taking_my_starving_friends_chips/" for comparison.

I have attached some examples. If you need, I can get a lot more examples from a lot more pages.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

This problem is present in a lot of Firefox versions. I can't remember if any of the very old versions of Firefox didn't contain this error.
I have tested this on Windows (XP, 7 and 10) and on Linux (Ubuntu, Xubuntu and Lubuntu). I have tested Firefox normal edition, Firefox developer edition and Firefox ESR.

EDIT: My previous comment is missing a few words. This comment is replacing my previous comment.

Testcase 1:
Go to "https://www.doomworld.com/forum/topic/68477-hocusdoom-released-in-idgames/?tab=comments#comment-1265795" with Firefox and preview and print that page.
Then, with Chrome, go to the same page and do the same thing.
Chrome is giving preview and printing correctly.

Testcase 2:
Go to "https://www.reddit.com/r/tifu/comments/ebq476/tifu_by_taking_my_starving_friends_chips/" with Firefox and preview and print that page.
Then, with Chrome, go to the same page and do the same thing.
Chrome is giving preview and printing a lot more things than Firefox.

The priority flag is not set for this bug.
:TYLin, could you have a look please?

For more information, please visit auto_nag documentation.

Testcase 2 (reddit.com) uses flex layout, so this is a duplication of bug 939897.

Testcase 1 (doomworld.com) use table layout, which needs further investigation.

Testcase 3:
Check attached files "Firefox www.jurasz.de_en_jarek_patchpae2.pdf" and "Chrome www.jurasz.de_en_jarek_patchpae2.pdf".
Repeat the steps made in Testcases 1 and 2 in the following url: www.jurasz.de/en/jarek/patchpae2

Testcase 4:
Check attached files "Firefox segaxtreme.net_threads_translating-grandia.24330_page-22" and "Chrome segaxtreme.net_threads_translating-grandia.24330_page-22".
Repeat the steps made in previous Testcases in the following url: segaxtreme.net/threads/translating-grandia.24330/page-22

Firefox www.jurasz.de_en_jarek_patchpae2.pdf

Chrome www.jurasz.de_en_jarek_patchpae2.pdf

Firefox segaxtreme.net_threads_translating-grandia.24330_page-22.pdf

Chrome segaxtreme.net_threads_translating-grandia.24330_page-22.pdf

Testcase 5:
Check attached files "Firefox GitHub.pdf" and "Chrome GitHub.pdf".
Repeat the steps made in Testcases 1 and 2 in the following url: github.com/adobe/brackets/issues/14952

The printing data loss bug on testcase 2 to 5 are all related to flex layout. They should be fixed by bug 1622935, and available in Firefox Nightly 78 (2020-05-13). As for testcase 1 (doomworld), some of the original post content is still cropped in printing. This is a different bug, and unfortunately not fixed by bug 1622935.

filipemaia, feel free to let us know if there is still some data loss in printing. I'll revise the title to emphasize the remaining bug.

Hi. Right now I'm using the Developer Edition 77.0b9 (32-bit).
I found two new testcases.
Sorry, I don't know if these two new testcases are fixed on Nightly 78 nor do I know if they are the same as bug 1622935.

Testcase 6:
https://www.bios-mods.com/forum/Thread-Unlock-request-for-a-older-Fujitsu-Siemens-Esprimo-Mobile-V5515
(the posts from www.bios-mods.com in Firefox are cropped; in the testcase 6 one of the posters name and avatar is not seen)

Testcase 7:
https://translate.google.com/translate?hl=&sl=auto&tl=en&u=https%3A%2F%2Fforum.softpedia.com%2Ftopic%2F793117-esprimo-v5515-upgrade-de-procesor%2F&sandbox=1
(this is the translation from Romanian to English using Google Translate of the page https://forum.softpedia.com/topic/793117-esprimo-v5515-upgrade-de-procesor/ ; I'm not attaching a Chrome PDF print of this testcase, because this is also broken in Chrome)

Please see the attached PDFs.

Thank you.

Re comment 20:

Thanks for reporting more sites!

Testcase 6:
The site is using a table layout. The "Shrink to fit" doesn't work perfectly all the time, so a possible workaround is to manually set the scale factor to a small number. In my testing, using 70% and US letter portrait mode looks OK to me. Also, note that the site has a "View a Printable Version" bottom near the bottom, which strips all the fancy border and leave the content. It should also help to print the essential part of the site.

Testcase 7:
Google translation wraps the original site in an <iframe>, so this looks like bug 1250348

Hi Ting-Yu Lin.

About Testcase 6, thank you for the workarounds.
Still, I hope that some day the "Shrink to fit" works without problems in Firefox, because in Chrome I tried with multiple border sizes and multiple paper sizes and it works without any problem.

Thanks for your hard work.

Hi.

One new testcase.

Testcase 8:
https://forum.ih8mud.com/threads/1kz-te-cracked-head.1093232
See TC8-forum.ih8mud.com-CHROME.pdf and TC8-forum.ih8mud.com-FIREFOX.pdf.

Thank you.

Re comment 26:

Thanks for the new testcase! Which version of Firefox are you using? Here's a sample printed by Firefox 78.0.2 on macOS. I expect this site should be printed more than the first page (though some of the images are still truncated. Maybe it's related to bug 1479119.)

Hi Ting-Yu Lin.

You are correct. I was using an older version (77.0b9 (32-bit) Win.). I've updated to version 79.0b7 (32-bit) Win. and tested again. Sorry about that.
With the newer version, I couldn't get any images to show (I tried portrait and landscape), but it seems that all the text was printed, so that is an improvement. I'm attaching a new pdf (portrait).

Thank you.

Re comment 30:

Good to know it works on Firefox 79. About the images missing, I notice the images on this site don't load until I scroll the page to them. So if I scroll the page down to the bottom, and then print, the pdf does include all the images.

Hiro, does the above issue because of the lazy loading of images? Please see the link in comment 26. There are images below this text: "I've flushed the rad as well and am running Toyota red at 60%." If yes, maybe we should disable the lazy loading of images when printing / print-preview?

(In reply to Ting-Yu Lin [:TYLin] (UTC-7) from comment #32)

Hiro, does the above issue because of the lazy loading of images? Please see the link in comment 26. There are images below this text: "I've flushed the rad as well and am running Toyota red at 60%." If yes, maybe we should disable the lazy loading of images when printing / print-preview?

Yes, I believe so, I can see there are a bunch of loading=lazy img elements.

Emilio has already written the fix in bug 1648064.

Hi Ting-Yu Lin. You are correct, if I scroll down on the page before printing, the images start to show and after that they start to print.
Hi Hiroyuki Ikezoe, it's good to know there is a fix for lazy loading.
Thank you both.

Hi.
I found a new bug, please see the attached two files with names "reddit bug reported on 19Nov2021" (https://www.reddit.com/r/crtgaming/comments/bk0zft/large_crts_43_us_169_eu/).
The top bar on that webpage (the one with the reddit logo and the search field and other icons) is printed in every page and it's covering/hidding text and images that should be displayed.
I'm on 95.0b9 win32-bit Dev.Edition.

The top bar on that webpage (the one with the reddit logo and the search field and other icons) is printed in every page and it's covering/hidding text and images that should be displayed.

Reddit uses "position:fixed" on the top bar (i.e. the <header> element). Quote the CSS position spec as follows.

The box’s position is fixed with respect to this reference rectangle: ... when attached to the page area is replicated on every page when the document is paginated.

That is, browser has to replicate that element in every page when printing. (The spec even has an example to demonstrate how to solve this issue using @media print)

Hi.
Just letting you know that printing is very much improved in the latest version (97.0b9), but doomworld still has problems.
Here is a new example:
https://www.doomworld.com/forum/topic/113359-pwad-and-gameplay-mod-loading-ubuntu/
I'll attached picture and pdf.

(In reply to filipemaia from comment #39)

Hi.
Just letting you know that printing is very much improved in the latest version (97.0b9), but doomworld still has problems.
Here is a new example:
https://www.doomworld.com/forum/topic/113359-pwad-and-gameplay-mod-loading-ubuntu/
I'll attached picture and pdf.

I'm afraid I wasn't clear enough in my last comment.
When I say "printing is very much improved in the latest version (97.0b9), but doomworld still has problems", I didn't mean that only doomworld has problems while printing. There are still other sites with problems (like reddit and ...).
What I meant was that I appreciate your effort and that Firefox printing is better than what it was 2 years ago.
Thanks.