1818088 - Firefox clips some text when printing PDF of sheet music (whether printing to PDF or to real printer)

Status: NEW

(Core :: Printing: Output, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1 (first page of "house of the rising sun" sheet music)

STR:

1. Load attached PDF in Firefox
2. Cmd+P to open print dialog.
3. Choose a print target (let's say save-to-PDF for simplicity, but it repro's with a real printer too) and click through to print.
4. Open the resulting PDF (or look at the printed page) and examine the 𝅘𝅥 = 92 text near the top left.

ACTUAL RESULTS:
The "92" glyphs are clipped at the top.

EXPECTED RESULTS:
No clipping.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: the buggy PDF output from printing from Firefox on macOS, with "92" clipped at the top

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: the expected/better PDF output, printed from Firefox on Linux

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: screenshot of the clipped text

Comment 4

[Daniel Holbert [:dholbert]]

I'm testing Firefox Nightly 112.0a1 2023-02-21, on macOS Ventura 13.2.1

Comment 5

[Daniel Holbert [:dholbert]]

There are a few behavior-changes here.

When examining the save-to-PDF output produced by my STR:

Change #1 (regression):

• 2021-04-28: No clipping, and text scales crisply when zoomed.
• 2021-04-29: The 92 glyphs are visibly clipped at the top, and all of the content (all musical symbols etc.) gets blurry when I zoom the save-to-pdf output in Preview.
  Pushlog range for this change:
  https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1005c275ed0f63d7ff2b003cff9c0e67b412a950&tochange=c00df77af50e0703d37188be7c57032713e6ef
  --> This was almost certainly the cairo update in bug 739096.

Change #2 (partial improvement):

• 2022-10-20: 92 is clipped, and all content is blurry (as-described for 2021-04-29 above)
• 2022-10-21: 92 is clipped, and all content looks crisp.
  Pushlog range for this change:
  https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=748e7c13aaf789296ec09bd18f735de8f89934da&tochange=d8c158f47023bcde55f9f217b9f3345be
  --> bug 1789482 gave us this partial improvement (specifically the gfx.cairo_quartz_cg_layer.enabled pref-flip there). Indeed, if I toggle that pref back to false in current Nightly, I get the blurry-content behavior.

So bottom line: this clipping issue is a regression from bug 739096; and it was originally part of a regression that introduced clipping and blurriness, but now we've just got clipping, after we activated the quartz-cg-layer backend in bug 1789482 (and supporting bug 1772225).

Comment 6

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 739096

:jfkthame, since you are the author of the regressor, bug 739096, could you take a look?

For more information, please visit auto_nag documentation.

Comment 7

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 739096

Comment 8

[Jonathan Kew [:jfkthame]]

Presumably this is a bug in the cairo-quartz font or rendering backend, where the bounds of those glyphs are incorrect for some reason.

Fortunately, it doesn't seem to be happening widely; all the other text in the PDF is unclipped. It may be something about the particular font used for those glyphs that's being mishandled.

Ideally, we'd come up with a standalone testcase based on extracting the suspect font from the PDF, to make it more manageable to investigate.

Comment 9

[David Shin[:dshin]]

(Drive-by: Font used here seems to be Edwin Bold, though I don't have a Mac to reproduce this)