1881137 - Issues with CultureAmp performance review "Export" printer-friendly version: extra blank pages between sections, and content getting progressively skinnier

Status: NEW

(Core :: Printing: Output, defect)

Description

[Daniel Holbert [:dholbert]]

STR

1. Authenticate at https://sso.mozilla.com/cultureamp
2. Visit https://mozilla.cultureamp.com/performance/evaluation_cycles/summary (or click Performance | Reviews)
3. Click the "Export" button at the top-right of a review. (This spawns a new-tab, which then automatically triggers a print-preview dialog)
4. Scroll through the print-preview dialog that appears. (I'm using Save-to-PDF as my print target, to reduce variables; but I get the same results for an actual printer.)

ACTUAL RESULTS:

• For me personally, my 2023 H2 Perf Review generates 23 pages of output in Firefox, vs. 5 pages of output in Chrome.
• The 5 pages of output in Chrome look like what-you-would-expect; the actual content, nicely fragmented.
• The 23 pages of output in Firefox have blank pages interspersed (sometimes right in the middle of a section), and the content area seems to be progressively skinnier on each page. Both of these issues (blank pages & narrowing) get worse the further I go in the document.

In particular:

• Page 1 looks fine.
• Page 2,3,4 are progressively narrower but generally fine. (Page 4 seems to only be using the left half of the page -- linewrapping unnecessarily when we hit the center of the page or therabouts.)
• Page 5 is blank. (1 page)
• Page 6 is narrower than page 4 was.
• Pages 7-8 are blank. (2 pages)
• Page 9 is about as narrow as page 6, maybe slightly narrower.
• Page 10-12 are blank. (3 pages)
• Page 13 is narrower still.
• Page 14-17 are blank (4 pages)
• Page 18 is narrower still and has the last bit of actual content.
• Page 19-23 are blank (5 pages)

Comment 1

[Daniel Holbert [:dholbert]]

I'll avoid posting the actual perf-review document that I'm hitting this with, for obvious privacy reasons, but I think I can generate a reduced testcase that triggers the same issue. So far, from poking in DOM inspector, the layout seems to be nested flexboxes, so there might be some flexbox fragmentation weirdness involved here.

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: testcase 1: just showing the progressively-skinnier issue

(In reply to Daniel Holbert [:dholbert] from comment #0)

the content area seems to be progressively skinnier on each page.

Here's a testcase for this part.

The abspos element (outlined in blue here) is quite tall, and hence it gets fragmented across many pages. But each fragment is skinnier than the previous one, and that's weird/unexpected.

it seems like we subtract away the margin-right again with each newly generated fragment, leading us to have a progressively-skinnier box on each page? I think I've seen this before, so this might be a dupe of some existing bug.

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: testcase 2: just showing the interspersed-blank-pages issue

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: testcase 3: showing both issues

Comment 5

[Daniel Holbert [:dholbert]]

(We might ultimately want to focus on testcase 1 or 2 here, and spin off a separate bug for the other one, but we can decide on that once we've got a diagnosis [or if we find that one of these testcases is covered by an existing bug report].)

Comment 6

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

The severity field is not set for this bug.
:jwatt, could you have a look please?

For more information, please visit BugBot documentation.

Comment 7

[Jonathan Watt [:jwatt]]

(We have other similar bugs like bug 563436, bug 581994, bug 649802 and bug 1122468.)

Comment 8

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

The progressively-skinnier issue in testcase 1 is fixed by bug 563436, but the interspersed-blank-pages issue in testcase 2 & 3 is still there.

Comment 9

[Daniel Holbert [:dholbert]]

The interspersed-blank-pages issue might be related to bug 1858571.

Comment 10

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

If I set layout.display-list.improve-fragmentation=false, I don't see the interspersed-blank-pages.