User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:70.0) Gecko/20100101 Firefox/70.0

Steps to reproduce:

Three different label printers are correctly configured (page size, resolution, etc.) in CUPS and working correctly. This happens on all printers with different drivers (Zebra & Intermec) and different size.

I want to print a label from web app in Firefox. The label is rendered correctly, the page size and orientation set correctly in the print dialogue.

Firefox prints the label 90 degree rotated in the middle of the label, half of it is cut off.

Monitoring /var/spool/cups gives the following results:

• a correctly rendered pdf file is saved to the spool directory
• the corresponding spool file contains a wrong page size, which is about A4 (confirmed by CUPS developers at GitHub, not sure what the units are)

If I do exactly the same from Chromium, where the resulting print-out is fine:

• a correctly rendered pdf file is saved to the spool directory (as in Firefox)
• the corresponding spool file contains the correct page size.

I paste here the content of the spool file for a 38 mm/1.5 inch wide and 19 mm/0.75 inch high label.
Firefox (wrong page size - 595.3x841.89):
^B^A^@^B^@^@^@^A^AG^@^Rattributes-charset^@^Eutf-8H^@^[attributes-natural-language^@^Een-gb^BB^@^Yjob-originating-user-name^@^BhlE^@^Kprinter-uri^@+ipp://localhost:631/pr>
Resolution^@^F203dpiB^@^NzeErrorReprint^@^ESavedB^@^KzePrintMode^@^ESavedB^@^HDarkness^@^B-1B^@
zeLabelTop^@^C200B^@^KzePrintRate^@^GDefault!^@^Ljob-priority^@^D^@^@^@2B^@^HPageSize^@^TCustom.595.28x841.89B^@^OzeMediaTracking^@^CWeb"^@^GCollate^@^A^@B^@ MediaType^>
job-sheets^@^DnoneB^@^@^@^DnoneB^@^QzeTearOffPosition^@^D1000!^@ number-up^@^D^@^@^@^AI^@^Xdocument-format-detected^@^Oapplication/pdfI^@^Odocument-format^@^Oappli>

Chromium (correct page size - 107.72x53.86):
^B^A^@^B^@^@^@^A^AG^@^Rattributes-charset^@^Eutf-8H^@^[attributes-natural-language^@^Een-gb^BB^@^Yjob-originating-user-name^@^BhlE^@^Kprinter-uri^@+ipp://localhost:631/pr>
Resolution^@^F203dpiB^@^QzeTearOffPosition^@^D1000B^@^HPageSize^@^SCustom.107.72x53.86B^@^HDarkness^@^B-1B^@
zeLabelTop^@^C200B^@
job-sheets^@^DnoneB^@^@^@^DnoneI^@^Xdocument-format-detected^@^Oapplication/pdfI^@^Odocument-format^@^Oapplication/pdfE^@^Hjob-uuid^@-urn:uuid:ffa2f26b-d558-382a-638f-b94>

Actual results:

Label is printed rotated because the wrong page size that is transferred to the printing system. The size of the content is correct, i.e. not scaled. The rotation is most likely due to the different aspect ratio (higher than wide, while label is wider than high).

Expected results:

The label should print on the label, as it does when sent from another browser (e.g. Chromium) or as pdf via lp.

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