1805477 - Pages-per-sheet doubled up with system dialog on macOS

Status: RESOLVED FIXED

(Core :: Printing: Setup, defect)

Description

[Jonathan Watt [:jwatt]]

On macOS, when you set up print preview and select multiple pages per sheet, that value is lost. That can result in some users misprinting and having to reprint.

Comment 1

[Jonathan Watt [:jwatt]]

Attachment: Bug 1805477 - Prevent pages-per-sheet on macOS being double applied by system print dialog. r=dholbert

Note: NSPagesAcross/NSPagesDown is internal API to Apple and is basically
unknown to the Internet. I discovered it by digging through printing structs in
a debugger while trying to find out how the pages-per-sheet information was
being communicated internally in Cocoa. However, after finding it, I see Google
knows about a grand total of 18 pages on the Internet that mention it, all as
part of debug info dumps. That's still helpful though, since it shows that
these two dictionary entries have been in use since at least 2008, giving some
confidence about backwards compatibility and that it will likely remain in use.

Related to these dictionary keys, Apple's official documentation claims that
there are similarly named keys called NSPrintPagesAcross/NSPrintPagesDown:

https://developer.apple.com/documentation/appkit/nsprintpagesacross
https://developer.apple.com/documentation/appkit/nsprintpagesdown

However, I couldn't get those to work, either to read values or to set values.
The references I could find to them on the Internet were in debug output and
people also stating they couldn't get them to work. I have to wonder if someone
at Apple changed the names at some point and forgot to update the
documentation?!

Finally, note that NSPrintPagesPerSheet is long deprecated and nowadays just
has a dummy value of "1" hardcoded.

https://developer.apple.com/documentation/appkit/nsprintpagespersheet

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f42cde0309b3
Prevent pages-per-sheet on macOS being double applied by system print dialog. r=dholbert

Comment 3

[Atila Butkovits]

Backed out for causing build bustages at nsPrintDialogX.

Backout link: https://hg.mozilla.org/integration/autoland/rev/5a2aac1feb784be71e029497969db1a25f581ec0

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=5f3b763b270b2e2dc6775a6f91ef64834192267e&selectedTaskRun=cy3ca_PvTjeNfjZEB87iyA.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=399560620&repo=autoland&lineNumber=46026

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/345c10ab15d2
Prevent pages-per-sheet on macOS being double applied by system print dialog. r=dholbert

Comment 5

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/345c10ab15d2

Comment 6

[Vlad Lucaci, Thunderbird QA (:vlucaci)]

Hello Jonathan,

Can you please provide steps to reproduce this issue on an affected build?

We cannot reproduce it on our end with the information given.