Closed Bug 1671252 Opened 4 years ago Closed 3 years ago

[Windows 10+] 1px at bottom cut off in non-maximized windows when coloured title bars and window borders are enabled

Categories

(Core :: Widget: Win32, defect)

Product:
Core
Component:
Widget: Win32
Version:
Firefox 81
Platform:
Desktop
Windows 10
Type:
defect

Tracking

()

Status:
VERIFIED FIXED
Milestone:
96 Branch
Tracking Flags:
Tracking Status
firefox-esr78 --- wontfix
firefox-esr91 --- verified
firefox81 --- wontfix
firefox82 --- wontfix
firefox83 --- wontfix
firefox94 --- wontfix
firefox95 --- verified
firefox96 - verified

People

(Reporter: rechdshraipfelehr, Assigned: emilio)

References

(Regression,
URL
)

Details

(Keywords: regression)

Attachments

(4 files)

Firefox border bottom window.png
16.70 KB, image/png
Details
screenshot
52.33 KB, image/png
Details
WFM
20.29 KB, image/png
Details
Bug 1671252 - Move Windows accent border to #navigator-toolbox. r=Gijs
48 bytes, text/x-phabricator-request
pascalc
: approval-mozilla-beta+
pascalc
: approval-mozilla-esr91+
Details | Review

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0

Steps to reproduce:

  1. Open a website with a 1px border, like this one:

<style>
body {
margin: 0;
height: 100%;
border: 1px solid red;
box-sizing: border-box;
}
</style>

  1. Make the window smaller so it's not maximized anymore (I don't know how this is called)

I'm using Firefox 81.0.2 on Windows 10 1909.

Actual results:

The border at the bottom is not visible. See attached screenshot.

Expected results:

The border at the bottom should be visible.

I can reproduce the issue on Nightly83.0a1 Windows10 if browser.tabs.drawInTitlebar = true.
The problem appears since Firefox72.

URL: data:text/html,<style>body {margin: 0...
Status: UNCONFIRMED → NEW
Has STR: --- → yes
status-firefox81: --- → wontfix
status-firefox82: --- → wontfix
status-firefox83: --- → affected
status-firefox-esr78: --- → wontfix
Component: Untriaged → Widget: Win32
Ever confirmed: true
Keywords: regression
OS: Unspecified → Windows 10
Product: Firefox → Core
Hardware: Unspecified → Desktop

Brendan, any idea what is going on here?

(moving out of widget because I think this is either a frontend or layout issue)

Component: Widget: Win32 → General
Flags: needinfo?(bdahl)
Product: Core → Firefox

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Win32' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Component: General → Widget: Win32
Product: Firefox → Core

Bad bugbug, no botsnack for you.

Component: Widget: Win32 → General
Product: Core → Firefox

[Tracking Requested - why for this release]: due to regression of bug 1492582, bottom 1px of content is cut off.

status-firefox96: --- → affected
tracking-firefox96: --- → ?

(In reply to Alice0775 White from comment #6)

[Tracking Requested - why for this release]: due to regression of bug 1492582, bottom 1px of content is cut off.

Can you clarify how to reproduce this? I can't seem to reproduce (Windows 10 21H1, 19043.1288). I've tried with different display scaling (100%, 200%, 150%) and the red bottom border is always visible. I restore the window by doubleclicking an empty bit of tabstrip. Tried with Nightly 95 and beta 94, same result for both.

Flags: needinfo?(alice0775)
Attached image screenshot —

mm, There are no special steps.
My environment,
Windows10 Home 19043.1288
Windows Settings, 140% in text scale, 100% in DPI scale.

Str:

  1. Start Firefox w/ new profile
  2. Open data:text/html,<style>body {margin: 0;height: 100%;border: 1px solid red;box-sizing: border-box;}</style>

Actual:
Red bottom border is not visible.

Flags: needinfo?(alice0775)
Attached image WFM —

Bizarre. I don't see this, even with exactly the same scaling settings.

Emilio, do you have ideas on how to gather more data here / figure out what's happening?

Flags: needinfo?(emilio)

On vmware, guest: Windows 10 Pro for Workstations 19043.1288, 100% in text scale, 100% in DPI scale.
I can also reproduce the issue.

Can't repro locally either... It seems likely to be a windows-specific off-by-one, probably similar to bug 1609129?

Flags: needinfo?(emilio)
See Also: → 1609129

Maybe bugbug was right after all...

Component: General → Widget: Win32
Product: Firefox → Core

Okay, I found the trigger that causes the problem in the Windows10 Settings.

Start > Settings > Personalization >
 Colors > Turn on "Title bars and window borders"

:Gijs, can you reproduce this when the above Windows10 Settings?

Flags: needinfo?(gijskruitbosch+bugs)

Thanks. Yes, with that option enabled I can reproduce the issue. I expect it's related to the fact that we put a border-top on the <html> DOM node, coloured with the accent colour, as instructed by that system pref. What I don't quite follow is why that causes this bug - everything else is using flexbox so should "just" resize accordingly, not end up slightly off-screen. Emilio, with now-solid STR, do you have any idea? I suspect some kind of rounding-related layout issue but I don't really know how to go looking for it.

Flags: needinfo?(gijskruitbosch+bugs)
Flags: needinfo?(emilio)
Flags: needinfo?(bdahl)
Summary: 1px at bottom cut off in non-maximized windows → [Windows 10+] 1px at bottom cut off in non-maximized windows when coloured title bars and window borders are enabled
Flags: needinfo?(emilio)

This works correctly. On the root it seems we hit this codepath:

https://searchfox.org/mozilla-central/rev/df18dd52da04ee2bad434b0ba2d9fcb196d4d15e/layout/xul/nsBoxFrame.cpp#514-525

And end up with an slightly-bigger-than-needed box. I haven't dug into what
changing this may entail, but given the root frame is special anyways (because
it affects window constraints etc) it's probably safer to do this.

Assignee: nobody → emilio
Status: NEW → ASSIGNED

It's not a rounding issue (if I set the border-width to 100px then we push stuff 100px to the bottom).

Pushed by ealvarez@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/220f3305e900
Move Windows accent border to #navigator-toolbox. r=Gijs

https://hg.mozilla.org/mozilla-central/rev/220f3305e900

Status: ASSIGNED → RESOLVED
Closed: 3 years ago
status-firefox96: fix-optional → fixed
Resolution: --- → FIXED
Target Milestone: --- → 96 Branch

Seems like a pretty trivial patch - did you want to nominate this for Beta/ESR approval?

Flags: needinfo?(emilio)

Comment on attachment 9251214 [details]
Bug 1671252 - Move Windows accent border to #navigator-toolbox. r=Gijs

Beta/Release Uplift Approval Request

  • User impact if declined: comment 0
  • Is this code covered by automated tests?: Yes
  • Has the fix been verified in Nightly?: Yes
  • Needs manual test from QE?: Yes
  • If yes, steps to reproduce: comment 13
  • List of other uplifts needed: none
  • Risk to taking this patch: Low
  • Why is the change risky/not risky? (and alternatives if risky): We're using the same border on win7/8.
  • String changes made/needed: none

ESR Uplift Approval Request

  • If this is not a sec:{high,crit} bug, please state case for ESR consideration: Trivial ui fix.
  • User impact if declined: see above
  • Fix Landed on Version: 96
  • Risk to taking this patch: Low
  • Why is the change risky/not risky? (and alternatives if risky): see above.
  • String or UUID changes made by this patch: none
Flags: needinfo?(emilio)
Attachment #9251214 - Flags: approval-mozilla-esr91?
Attachment #9251214 - Flags: approval-mozilla-beta?
Flags: qe-verify+
QA Whiteboard: [qa-triaged]

Comment on attachment 9251214 [details]
Bug 1671252 - Move Windows accent border to #navigator-toolbox. r=Gijs

Approved for our last 95 beta, thanks.

Attachment #9251214 - Flags: approval-mozilla-beta? → approval-mozilla-beta+

Verified as fixed on Windows 10 x64 on Firefox Nightly 96.0a1.

status-firefox95: fixed → fix-optional
status-firefox96: fixed → verified

Reverting accidental change to fx95 status flag to ensure this gets verified on beta too once builds are available.

status-firefox95: fix-optional → fixed
Attachment #9251214 - Flags: approval-mozilla-esr91? → approval-mozilla-esr91+

Verified as fixed on Firefox Beta 95.b12 and on Firefox 91.4.0esr on Windows 10 x64.

Status: RESOLVED → VERIFIED
QA Whiteboard: [qa-triaged]
status-firefox95: fixed → verified
status-firefox-esr91: fixed → verified
Flags: qe-verify+
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