1722842 - Print quality is severely degraded printing PDF on thermal label printer

Status: RESOLVED DUPLICATE of bug 1721127

(Core :: Printing: Output, defect)

Description

[Adam Zey]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36

Steps to reproduce:

Print a Canada Post PDF shipping label from Shopify on a Rollo thermal printer

Actual results:

Low resolution and jagged print quality makes shipping labels unusable. Barcodes are disrupted and small text is unreadable. Appears to be trying to scale the image (which doesn't work well on thermal printers) and outputting at a lower resolution than expected.

Expected results:

Print quality is good, as it was before the most recent Firefox update. I tried a portable version of Firefox 78 ESR and the quality was as expected. This may be a regression caused by 1720621, where another user also reported it caused print quality issues on his Zebra thermal printer.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::PDF Viewer' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Adam Zey]

Further information, I've tested various Firefox versions. The print quality issue does not happen in 89.0.2, and first appears in 90.0.0. This may rule out the fix for bug 1720621 as the cause. So some change that happened between 89.0.2 and 90.0.0 caused the print quality issues on thermal printers.

Comment 3

[jscher2000]

Hi Adam, can you print the label repeatedly without running up postage costs? If so, you could use the Mozregression tool to triangulate the change.

https://mozilla.github.io/mozregression/

Comment 4

[Adam Zey]

I can just reprint the same label repeatedly, it's just the cost of consumables and the time taken to manually authenticate to Shopify every time. I'll try to do it soon.

Comment 5

[Adam Zey]

I ran it against regressions, and twelve shipping labels later, it spat out this message:

2021-07-29T18:48:50.040000: INFO : Narrowed integration regression window from [d735e197, 6dc40766] (3 builds) to [d735e197, 7387be4b] (2 builds) (~1 steps left)
2021-07-29T18:48:50.046000: DEBUG : Starting merge handling...
2021-07-29T18:48:50.046000: DEBUG : Using url: https://hg.mozilla.org/integration/autoland/json-pushes?changeset=7387be4b195f3f266410d8faafbaf80f8176e293&full=1
2021-07-29T18:48:50.046000: DEBUG : redo: attempt 1/3
2021-07-29T18:48:50.046000: DEBUG : redo: retry: calling _default_get with args: ('https://hg.mozilla.org/integration/autoland/json-pushes?changeset=7387be4b195f3f266410d8faafbaf80f8176e293&full=1',), kwargs: {}, attempt #1
2021-07-29T18:48:50.048000: DEBUG : urllib3.connectionpool: Resetting dropped connection: hg.mozilla.org
2021-07-29T18:48:51.013000: DEBUG : urllib3.connectionpool: https://hg.mozilla.org:443 "GET /integration/autoland/json-pushes?changeset=7387be4b195f3f266410d8faafbaf80f8176e293&full=1 HTTP/1.1" 200 None
2021-07-29T18:48:51.092000: DEBUG : Found commit message:
Bug 739096 - Don't leave the shm field uninitialized in cairo_xlib_display. r=jrmuizel

This resulted in a valgrind failure on autoland.

Submitted upstream at https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/170.

Differential Revision: https://phabricator.services.mozilla.com/D113756

2021-07-29T18:48:51.092000: DEBUG : Did not find a branch, checking all integration branches
2021-07-29T18:48:51.094000: INFO : The bisection is done.
2021-07-29T18:48:51.094000: INFO : Stopped

That doesn't really make sense to me (this is an issue with printing a PDF on Windows 10, not a display issue on X11), but I'll attach the log and a screenshot of the progress if it helps.

Comment 6

[Adam Zey]

Attachment: mozregression progress screenshot

A screenshot of running mozregression to identify where the printing issue appeared.

Comment 7

[Adam Zey]

Attachment: The log of running mozregression

The log from running mozregression to narrow down the print problems

Comment 8

[Adam Zey]

Attachment: Photo of before/after

This photo shows the before and after of two shipping labels printed during the mozregression session. Some personal info is censored in red.

Comment 9

[jscher2000]

Thank you for running that!

The same change was fingered in bug 1721127 "Low res print on Zebra label printer after update 90" -- referring to the Zebra ZD410 thermal label printer. Is that the same model/brand you use, or a different printer having the same issue?

Comment 10

[Adam Zey]

I have a Rollo thermal label printer (https://www.rollo.com/), model X1038 (as far as I know this is the only printer model they have ever made) running driver 1.4.5 on Windows 10 21H1 (19043.1110). I'm printing Canada Post shipping labels generated by Shopify. All the order fulfillment and shipping label stuff is all web-based so I'm buying a shipping label in Shopify's interface and then hitting print from the browser's PDF viewer.

As far as I can tell, it's essentially the same technology/type of printer as the Zebra model, with the same basic capabilities (300 dpi monochrome thermal printer), except that the Zebra prints 2.2" wide labels and the Rollo prints up to 4.16" wide labels (to support 4x6 standard shipping labels).

Comment 11

[Jonathan Watt [:jwatt]]

(In reply to Adam Zey from comment #5)

I ran it against regressions, and twelve shipping labels later, it spat out this message:

Many thanks for doing that.

Since this is essentially the same issue as bug 1721127 and jfkthame has started looking into that bug I'll dup it to that bug.