Platform/Layout/Printing and fragmentation

This page provides information about our efforts in 2020 to improve the platform parts of printing and fragmentation in Firefox. Given how closely linked the frondend and platform parts of printing are, this will inevitably involve some frontend work too.

Rationale

Support for printing in Firefox has historically been poorly maintained, and is currently in a dismal state compared to other browsers. There are two main areas for improvement:

• Printing UX: Firefox’s printing UI/UX lacks consistency and is complicated and confusing compared to the competition. Print settings are displayed differently across operating systems, different methods of accessing printing lead to different dialogs, and print preview is not displayed by default on macOS.
• Printing output: There is a significantly-sized backlog of user-reported bugs related to print output (for both printing devices and PDF export). Some of these bugs include cases where printing fails completely, several pages are missing, or the printed layout is just incorrect.

Managing bug list

The tables of bugs below are managed automatically using the `whiteboard` field in bugzilla.

• To add a bug on the printing backlog add "[print2020]" to the whiteboard
• To add a bug to the fragmentation backlog add "[frag2020]" to the whiteboard
• To move a bug to target a specific release, append "_vXX" to the whiteboard field (e.g. "[frag2020_v73]")

NIGHTLY 76

Merge to beta: 2020-04-06 (start: 2020-03-09; freeze: 2020-04-02; release: 2020-05-05)

Fragmentation

No results.

0 Total; 0 Open (0%); 0 Resolved (0%); 0 Verified (0%);

Printing

No results.

0 Total; 0 Open (0%); 0 Resolved (0%); 0 Verified (0%);

BACKLOG

Fragmentation

Full Query

ID	Summary	Assigned to	Resolution
179135	top:auto blocks with position:absolute misplaced when printing
267029	Absolutely positioned elements all print on first page, and the ones that don't fit aren't shown		WORKSFORME
649802	Abspos with margin gets progressively skinnier on each printed page		DUPLICATE
1250348	Tall <iframe> elements are truncated at page boundaries (instead of being split across pages, like tall images are)
1318856	when printing a tall image (or SVG graphic), it is truncated rather than split across pages
1344992	Lost printing content if specify the position:absolute and transform style.		INVALID
1417615	[Layout] Content truncated when printing a page containing a CSS grid with large row		FIXED
1468369	abs.pos. element immediately after a forced page break does not render
1479119	Long images cut off after first page when printing		DUPLICATE
1520749	Fails to print all slides from Remark.js slideshow		DUPLICATE
1569436	Butterick’s Practical Typography doesn't print to PDF correctly (abspos hypothetical position on non-first page not working properly)
1574684	www.specsavers.co.uk doesn't fully print		INCOMPLETE
1606540	printing problem when fragmenting tables		DUPLICATE
1633936	Add telemetry to determine how much content is clipped during printing
1648903	Printing A4 pages with abspos precisely-measured abspos content is faulty
1665214	When "slicing" printing-improvement preserves overflow from a clipped line-box or grid row, shift down the line or grid row on the next page to leave space for the expected overflow	Mats Palmgren (inactive)	FIXED
1674682	Content overlap when fragmenting with fixed height content
1680728	Yahoo search page background-image is shifted/clipped in Print Preview, if WebRender is enabled (with "background-attachment: fixed")
1681079	Print preview should override the position of right aligned page elements on print selection

19 Total; 19 Open (100%); 0 Resolved (0%); 0 Verified (0%);

Printing

Full Query

ID	Summary	Assigned to	Resolution
231068	new Page Header or Footer Option -- just Date (no Time)
454059	Creating PDF of web page: hyperlinks are lost.	Jonathan Kew [:jfkthame]	FIXED
659715	Consider preserving scroll position of iframes & other scrolled regions when printing
1249214	Scale canvas passed to mozPrintCallback to match printer resolution
1432651	Disentangle RemotePrintJobChild from nsPrintSettings, and kill off nsPrintSession	Jonathan Watt [:jwatt]	FIXED
1444078	Printing to 300x600 dpi label printer is half width
1657896	Print selection from BBC articles is sometimes missing the first letter of the selection
1657906	Text is displayed as cut-off in both print preview and print job's output for a specific bbc article
1657973	Support generation of tagged (accessible) PDFs
1658558	[ARM] Pages with various formats are not printed completely (several letters are arbitrarily missing)
1660223	Crash in [@ gtk_printer_get_name]	Daniel Holbert [:dholbert]	FIXED
1660921	Clone scroll positions in print documents		DUPLICATE
1662934	Investigate if there is a better way to fix double-scaled printing on macOS
1663556	Crash in [@ nsFrameLoader::MaybeCreateDocShell]		WORKSFORME
1663911	Crash in [@ initializeNonMetaClass]		WORKSFORME
1664253	Try not creating a PrintTarget for print preview.
1664413	Printing doesn't use current session cookies when in private mode	Emilio Cobos Álvarez (:emilio)	FIXED
1664860	The footer is cut off in Landscape mode when on paper on Windows 7 (with specific printers)
1665837	Button-text on network error pages is hard to read (dark-on-dark) when printed
1666677	Printing hidden frame causes tab crash in Firefox 80, and "An error occurred while printing" error in 81 & newer if you're using legacy print dialog		WORKSFORME
1666825	Online bank statement page not printing correctly (at Smile Bank UK)		DUPLICATE
1668400	Optimization: avoid needless reflow for page-range changes
1669365	BUG REPORT 81.0.1 (64 BIT) Firefox does not permit printing to any installed PDF app. Will not work with NuancePDF or native PDF in Windows.		INCOMPLETE
1669815	Remove now-useless "aInRange" outparam from nsPrintJob::PrintPage (and simplify nsPagePrintTimer::StartTimer() which consumes it?)	Jonathan Watt [:jwatt]	FIXED
1669910	Firefox draws the header/footer at the extreme edge of writeable area, which can lead to clipped header/footer in some situations (e.g. if printer lies about printable region, or if user prints to PDF and then prints that PDF to a physical printer)
1670645	Printing the source page is extremely slow		WORKSFORME
1670887	Print selection (context menu) images on some of the top sites are broken in print preview
1673147	Print Problem on EPSON LX-310 After Update 82.0		INCOMPLETE
1673248	PDF prints boxes where there is a space on macOS with Canon printer		INCOMPLETE
1674390	printing action changed and dont work well like last.		INCOMPLETE
1679041	Firefox doesn't allow page layout area to be inflated with negative @page margins
1681183	Tab-modal print dialog's "Margins: None" option should allow users to print with page margins actually set to 0, regardless of unwriteable area	David Shin[:dshin]	FIXED
1681206	@page margin:0 seems to be special and does not behave the same as margin:0.01px w.r.t. non-printable areas
1681214	Users' print-dialog margin choices aren't respected, if the content uses "@page { margin: ... }"		DUPLICATE
1683317	Output copies are doubled for a specific document
1683558	Scaling pages in print preview is not applied on the actual print		WORKSFORME
1695647	Printing to a paused printer on macOS silently does nothing
1704178	Remove dead printing code that can't be executed in a tab-modal-printing world	Jonathan Watt [:jwatt]	FIXED
1328072	[UX] [e10s] print preview opens print preview instead of showing alert like non-e10s (if printer was't found)
1631440	[meta] Platform support for the new print preview design
1651654	Black pages on Print preview for icq.com page
1654497	"Cannot print this document yet..." dialog no longer appears, when printing mid load.
1657489	Zooming print preview in new print UI flickers, clamps at 100%
1660474	Table border in Print Preview cut-off when window is narrower
1661121	Linked tiles at https://www.mozilla.org/en-US/ can be hovered / dragged *in print preview mode*
1661623	Text with high contrast mode in print preview is hard to read
1661691	ctrl+wheel zoom on print preview is unreliable
1662135	New print preview UI very janky scrolling documents with multiple pages		WORKSFORME
1662302	Assertion failure: child->IsDocument(), at src/dom/base/Document.cpp:12176
1662367	print preview shouldn't reuse previously used page format for PDFs, initially always portrait used, even for landscape PDFs
1662373	Print Preview of PDF - swapping to landscape mode shows only part of a page
1662534	Headers/footers don't appear when saving to PDF with margins set to None
1663672	Print preview is blurry with a certain configuration
1668208	Save to PDF's print preview cuts off content in vertical frames test page
1668769	User can interact with some links in print preview
1669191	Crash in [@ OOM | unknown | NS_ABORT_OOM | PLDHashTable::Add | gfxFontGroup::BuildFontList]		WORKSFORME
1669263	Sometimes, tab-modal Print Preview briefly flashes a higher-zoom version of the document, when you've made a small change to a print setting
1669469	No draggable action should be allowed in print preview
1669647	The background of a certain iframe is not steady in Print preview
1670287	Elements not supported by Cairo appear in Print Preview despite not appearing in Print output
1670638	[Reader View] Borders are not displayed in print preview
1674365	Improve print preview for printers with very long potential pages, for example receipt printers.
1676188	Cross origin iframe’s content is not displayed while using window.print() with fission enabled	Emilio Cobos Álvarez (:emilio)	FIXED
1679123	[mac] Print preview - focus ring shown in preview on part of page
1679153	Buttons from about:sessionrestore disappear when deselecting Print Backgrounds in Print Preview
1679392	GIF file fails to render sometimes while changing orientation or scale settings		DUPLICATE
1679397	Print preview repainting at small scales looks fuzzy
1679405	[Windows] System dialog opens after trying to save the file with “Save to PDF”		WORKSFORME
1680153	Scrolling is janky with the pages per sheet option
1680728	Yahoo search page background-image is shifted/clipped in Print Preview, if WebRender is enabled (with "background-attachment: fixed")
1681284	Some animations are played inside the Print preview
1689211	Print problems after auto-update to 85 on Windows 7 32-bit PC		INCOMPLETE
1558907	Open the print progress dialog from the frontend instead of the core printing code	Jonathan Watt [:jwatt]	WORKSFORME
1632275	Print to PDF should add the file to the Downloads list, otherwise these file are very hard for users to find
1657733	Audit tests that only run with print.tab_modal.enabled=false	Jonathan Watt [:jwatt]	FIXED
1658285	Print preview gets closed if the tab is moved to a new window
1658414	Print sheet does not have a way to add a printer
1658446	print preview: 'Scale' value should be shown/labeled as percentage ['%']
1658749	Middle Click scroll is not working correctly in new Print Preview		FIXED
1659782	Move the print preview browser into print.html		WONTFIX
1660111	[meta] Add automated tests for new print dialog		INACTIVE
1660468	[RTL] When a scrollbar is present in new Print UI options sidebar, changing an option from a dropdown will cause the next clicked dropdowns to appear misaligned with their `select`
1660520	Setting margins to 0.1 actually sets them to 0.100000001490116 (at least on Windows)
1660638	Please provide feature of Zoom-In/Out and tool button for print image in new print preview dialog
1660929	Prepopulate the system print dialog with all settings selected in the tab modal print preview doorhanger
1661663	Popular sites prevent the print preview Margins menu from working (users need a way to override @page margins)	Mark Striemer [:mstriemer]	FIXED
1661719	Changes made inside the new Print modal are kept for the old UI as well
1661751	Firefox print dialog doesn't get past throbber & "Preparing Preview", starting in Firefox 80		INCOMPLETE
1662239	Multiple redundant paper size entries returned in the paperList
1662786	No longer have the ability to cancel or monitor print progress (Implement some sort of print queue user interface)
1663005	If "save to pdf" is selected printer, try to copy over as many current settings as possible to the system dialog.
1663019	Print headers and footers & Print Backgrounds options are available for pdf documents		DUPLICATE
1663366	[Mac] Tab-modal print UI uses old dropdown menu appearance	Emilio Cobos Álvarez (:emilio)	FIXED
1663436	No longer able to change header/footer strings, even via "Print using system dialog..." escape hatch		WONTFIX
1663712	Explore fetching and caching printer information before users initiate printing	Mark Striemer [:mstriemer]
1663801	Only call saveSettingsToPrefs in the frontend code when the user actually prints		WONTFIX
1664415	Unexpected title for error-message dialog on a Print operation	Jonathan Kew [:jfkthame]
1668043	It should not be possible to interact with the tab content (e.g. using find-in-page) while tab-modal Print UI is open
1668072	opening print dialog opens it behind already open HTTP auth prompt, should be on top
1668453	Scroll print preview on PgUp/PgDown/Home/End when they would otherwise do nothing
1668794	[Linux] Paper size naming shows an additional “Borderless” after every option		WONTFIX
1668855	ctrl + +/- zooms the underlying page, not print preview
1669467	Print preview - tapping left-right should select between Portrait-Landscape options instead of scrolling between the options
1669699	Space height inconsistency after error messages inside the new Print modal
1669904	Stop using PrintUtils.getPrintSettings in the new printing UI
1670027	Print selection is disabled inside the system modal if the print preview destination was set to “Save to PDF”	Matthew N. [:MattN]	FIXED
1670037	Get rid of the DeferredTask code in print.js
1670110	Consider moving the "Paper size" field outside the collapsed-by-default "More settings" section
1670135	Add user interface to allow users to collate their printouts when printing multiple copies
1670871	Limit the number suggested inside the margins warning message to two decimals	Hanna Jones [:hjones]	FIXED
1670912	[macOS] Increase/Decrease buttons are different in Print Preview
1673908	Overextended Paper size dropdown at fullscreen exit for Foxit option (version <10 )
1675462	Print preview - Swapping from Scale to Fit To page and repeating with invalid scale should reset to previous valid value instead of 100
1675474	Two OS print modals can be triggered at the same time
1677327	Add 'Save PDF' option in modal print dialog on macOS
1678319	Print preview displays the webpage in Portrait mode for several Destinations while the Landscape option is active and opens the old System dialog on print/save		WORKSFORME
1678586	The Selection radio button from the system dialog panel is disabled if the system dialog was opened before the print preview finished loading
1678982	Clicking in the middle of the Scale arrows increases the scale while having a caret displayed
1678983	Print Preview - disable scale carets when values reach max or min values accordingly
1679389	Max scale values are different between new and system modal
1679515	Low Ink/toner levels notification should be displayed on the new modal as well
1679535	Most of the new Print modal options are inaccessible on destination change if previously a print action was made using Foxit reader with the old modal		DUPLICATE
1681908	Print Preview - adjust sheet indicator focus ring so it doesn't falsely show as being of a bigger size than button/needed
1681941	Tooltips on sheet indicator buttons are not shown for the second hover action if the sheet indicator focus is not removed	Emma Malysz	FIXED
1688597	Canceling the file picker while printing an about local page locally blocks the print preview in a “Printing…” state
1691381	The paginator’s “first page” and “last page” buttons extremities are transparent when shrinking the browser window
1691420	Consider making the preview have initial focus instead of the destination.
1693069	When users choose "Customised" as their "Pages", automatically focus the range field	Matthew N. [:MattN]	FIXED
1693989	PDF content gets clipped when printing, if it's too close to page edge (with no way to shrink to fit printable area)
1695645	"Sheets of paper" does not update when selecting "Print on both sides"	Haik Aftandilian [:haik]	FIXED
1712104	Add a preference 'print.prefer_system_dialog' to allow printing directly via the system print dialog	Jonathan Watt [:jwatt]	FIXED
1140929	Have nsPrintJob not block on modal nested event loop for print settings	Jonathan Watt [:jwatt]	FIXED
1521655	[meta] Support client-side printing in Google Docs and GSuite (Google Workspace)		FIXED
1558588	Remove the code that opens the print progress dialog from the core printing code	Jonathan Watt [:jwatt]	FIXED
1569247	[meta] Adding new telemetry printing-related probes
1615908	Consider saving only one set of print settings (instead of per-printer settings)
1621136	Write some firefox-source-docs.mozilla.org documentation for printing	Jonathan Watt [:jwatt]
1639844	Provide access to the native printer resolution through nsIPaper
1640533	Audit whether MOZ_CAN_RUN_SCRIPT annotations for nsPrintJob functions are correct/necessary or not
1651112	[meta] Expose printer specific information using nsIPrinterList and nsIPrinter to support the new printing UI
1657854	Only allow nsPrinterList objects to be created in the main process on all platforms.	Jonathan Watt [:jwatt]	FIXED
1658076	Add collation support to nsIPrintSettings
1658394	Add per-paper-size duplex information for CUPS printers
1660602	Profile janky rendering of print preview documents		WORKSFORME
1660885	Make nsIPrinterList::GetNamedOrDefaultPrinter always return a printer, if any are available	Emily McDonough [:alaskanemily]
1660905	Add nsIPrinter::CheckConnection to determine if a printer can be reached	Emily McDonough [:alaskanemily]
1660997	Deduplicate out common code in nsPrintSettingsWin::InitWithInitializer and nsPrintSettingsWin::CopyFromNative
1661294	Retrieve Native Resolution (DPI/PPI) Information For nsIPrinter
1661706	Crash in [@ initializeAndMaybeRelock]		WORKSFORME
1662471	Pref `print.always_print_silent` sometimes silently does nothing	Emilio Cobos Álvarez (:emilio)
1662626	Investigate whether the platform printing code is compatible with scaling > 100%
1663129	Crash in [@ mozalloc_abort | moz_xmalloc | NS_NewDOMEvent]		WORKSFORME
1663290	Consider making afterprint event fire after spinning the event loop	Emilio Cobos Álvarez (:emilio)
1663623	Assertion failure: !chan (Why is there a document channel?), at toolkit/components/windowwatcher/nsWindowWatcher.cpp:1016
1663629	Crash in [@ g_sequence_iter_get_sequence]		WORKSFORME
1663702	Make nsFrameLoader::Print support cancellation and progress reporting
1663753	Add telemetry to measure the time platform printing code takes to create/update/scroll print/preview documents
1664469	Get rid of nsPrintData
1664489	Print preview telemetry for the legacy UI is broken	Jonathan Watt [:jwatt]	WONTFIX
1664782	Return the paper list directly from nsPrinterListBase::GetFallbackPaperList without using a Promise
1666914	Printer Paper Size Mismatch		INCOMPLETE
1666937	Lazily add mDNS/Bonjour/Avahi printers to the print UI on CUPS platforms (missing printers)
1667260	Document exactly what settings the nsIPrintSettings returned by nsIPrinter.createDefaultSettings has set
1668210	Prevent print settings being saved to unprefixed prefs on non-Android	Jonathan Watt [:jwatt]	FIXED
1668813	On Ubuntu, the Color Mode dropdown is not locked to Black&White for B&W printers
1669329	[mac] Scaling value is not reflected in native print dialog
1669385	Replace nsIPrintSettings.paperWidth/paperHeight/paperSizeUnit with a single setter
1669762	Rename some attributes in nsIWebBrowserPrint.idl with s/page/sheet/
1674155	[macOS] Print preview displays wrong paper size if several steps are performed		WORKSFORME
1676828	[macOS 11] Default printer settings are different than of the other os's
1684952	Print jobs with complex print ranges will always print the pages in ascending order, even if the user's range has them in some other order
1685476	Print selection via context menu & via the new modal is not reflected inside the system dialog
1695552	macOS Printer Status Icon
1722063	MacOS - New Firefox Modal Print Dialogue Does Not Support Dynamic Airprint Printers		DUPLICATE
1785279	Combine mCreatedForPrintPreview, mIsDoingPrinting and mIsCreatingPrintPreview
844090	landscape pdfs are printed portrait with pdf.js		FIXED
1282045	print pdf with both orientations		DUPLICATE

177 Total; 177 Open (100%); 0 Resolved (0%); 0 Verified (0%);

NIGHTLY 75

Merge to beta: 2020-03-09 (start: 2020-02-10; freeze: 2020-03-05; release: 2020-04-07)

Fragmentation

No results.

0 Total; 0 Open (0%); 0 Resolved (0%); 0 Verified (0%);

Printing

Full Query

ID	Summary	Assigned to	Resolution
855889	Remove "print.use_global_printsettings" pref	Jonathan Watt [:jwatt]	FIXED
1430658	Saving of print settings inconsistently handles prefs	Jonathan Watt [:jwatt]	FIXED
1552966	Convert the printing code from DocShellTree* to BrowsingContext	Jonathan Watt [:jwatt]	FIXED
1606512	[macos] Save to PDF feature defaults filename to untitled.pdf instead of the title of the webpage.	Jonathan Watt [:jwatt]	FIXED
1618909	Remove nsPrintJob::GetDocumentName	Jonathan Watt [:jwatt]	FIXED
1619403	Merge nsPrintJob's GetDisplayTitleAndURL and GetDocumentTitleAndURL	Jonathan Watt [:jwatt]	FIXED

6 Total; 6 Open (100%); 0 Resolved (0%); 0 Verified (0%);