1919917 - [macOS] Selecting "Pages Per Sheet: 2" in Firefox print dialog causes System Print Dialog to mistakenly switch to Landscape orientation

Status: NEW

(Core :: Printing: Setup, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:

1. In Firefox on macOS, load the attached testcase (or any multipage document will do)
2. Cmd+P to open print dialog.
3. Choose an actual printer as the print target (not the built-in Save to PDF print target)
4. Expand "More Settings", and choose "Pages Per Sheet: 2".
5. (optional) Observe: Firefox's print dialog still correctly reports that you're using "Portrait" page-orientation, and the preview shows 2 side-by-side portrait-oriented pages on a Landscape-oriented sheet.
6. Click "Print using the system dialog..."
7. Look at the dialog's "orientation" settings. And optionally, proceed with the print operation.

ACTUAL RESULTS:
The System Print Dialog shows "orientation: Landscape by default.
If you complete the print operation, you do indeed end up with two Landscape-oriented pages on a portrait-oriented sheet.

EXPECTED RESULTS:
The System Print Dialog should show "Orientation: Portrait" (matching what I picked in the Firefox print dialog).
If you complete the print operation, you should end up with two portrait-oriented pages on a landscape-oriented sheet (matching what Firefox's preview showed).

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: expected print output

Just to illustrate the issue here, I'll attach the expected vs. actual results that I get (using a virtual PDF printer from printer-driver-cups-pdf on an Ubuntu server as my "real printer" print target here).

First, here's the expected results -- this is what I get if I skip step 6 and just print entirely from Firefox's own print dialog.

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: actual print output

vs. here's what I get if I include step 6 and click out to the system print dialog to complete the print operation.

Comment 4

[Daniel Holbert [:dholbert]]

One other unwanted outcome from this bug: the mysterious "Landscape" orientation-setting here is sticky, so the next time you try to print, we default to "Landscape" as the print orientation in the Firefox print dialog, even though the user never actively chose that orientaiton.

(This sorta makes sense given that we somehow toggle that option when launching the system-print-dialog during the STR here, but it's bizarre from a user's point-of-view.)