2058110 - jal.co.jp - Hero section slider stuck in a loading animation loop

Status: VERIFIED FIXED

(Web Compatibility :: Site Reports, defect, P1)

Description

[Calin Tanase]

Attachment: image.png

Environment:
Operating system: Windows
Firefox version: Firefox 153/155

Preconditions:

• Clean profile

Steps to reproduce:

1. Navigate to: https://www.jal.co.jp/ja-jp/
2. Observe the hero section.

Expected Behavior:
The slider gets displayed.

Actual Behavior:
Slider stuck in a loading animation loop. (however the edges of the slider images are visible)

Notes:

• Reproducible on the latest Firefox Release and Nightly
• Reproducible regardless of the ETP setting
• Works as expected using Chrome

Comment 1

[AutoWebCompat]

Attachment: Reproduction steps generated by autowebcompat bot

The reported issue reproduces in Firefox. Loading https://www.jal.co.jp/ja-jp/ in Firefox shows the hero/slider section stuck in a perpetual loading spinner animation. Only the far-right edge of a slider image is visible; the main slide never renders, and the spinner keeps looping while the slide indicator dots and pause control are shown beneath it. This matches the report (slider stuck in a loading animation loop with edges of the slider images visible). The behaviour persisted across repeated screenshots taken over time, confirming it is stuck rather than merely loading slowly.

The Chrome cross-check could not be completed: every attempt to load the page in the automated Chrome instance returned an Akamai "Access Denied" bot-detection page (https://errors.edgesuite.net/...), so Chrome never reached the actual site. Firefox loaded the real site normally. The report states the slider works as expected in Chrome, which is consistent with a Firefox-specific web-compat issue, but I was unable to independently verify the Chrome behaviour, so chrome_reproduced is left unconfirmed.

Comment 2

[AutoWebCompat]

Attachment: Screenshot generated by autowebcompat bot

Comment 3

[BugBot [:suhaib / :marco]]

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.

Comment 4

[Alice0775 White]

Regression window:
https://hg-edge.mozilla.org/integration/autoland/pushloghtml?fromchange=dd30b6f39841c14c0463b957712f231188c40369&tochange=7862376f4564170615e7e5d4c3d25c4b5a493420

Tentatively, marking Bug 1076583 as a regression.

Comment 5

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1076583

:emilio, since you are the author of the regressor, bug 1076583, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 6

[Emilio Cobos Álvarez [:emilio]]

Seems they're using this slider library: https://bxslider.com/

They have some preloadSelector stuff but debugging it is hard because they block me after a reload or two it seems...

Comment 7

[Emilio Cobos Álvarez [:emilio]]

Attachment: Rough version of what's going on

img.complete is false but the load/error events still not fire.

Comment 8

[Emilio Cobos Álvarez [:emilio]]

Ok, I could catch it on rr, relevant stack:

#0  RefPtr<ImageLoadTask>::assign_assuming_AddRef (this=0x7f8328733c20, aNewPtr=0x7f831d3f4f90)
    at ../../dist/include/mozilla/RefPtr.h:65
#1  RefPtr<ImageLoadTask>::assign_with_AddRef (this=0x7f8328733c20, aRawPtr=0x7f831d3f4f90)
    at ../../dist/include/mozilla/RefPtr.h:60
#2  0x00007f83351c8e7d in RefPtr<ImageLoadTask>::operator= (this=0x7f831d3f49e0, aRhs=<optimized out>)
    at ../../dist/include/mozilla/RefPtr.h:186
#3  nsImageLoadingContent::QueueImageTask
    (this=0x7f8328733c10, aSrcURI=<optimized out>, aSrcTriggeringPrincipal=0x7f832b7a2de0, aForceAsync=true, aAlwaysLoad=false, aNotify=false) at ../../../dom/base/nsImageLoadingContent.cpp:226
#4  0x00007f833734c263 in mozilla::dom::HTMLImageElement::BindToTree (this=0x7f8328733b80, aContext=..., aParent=...)
    at ./../../../dom/html/HTMLImageElement.cpp:465
#5  0x00007f8335320df3 in mozilla::dom::Element::BindToTree (this=0x7f83287a60d0, aContext=..., aParent=...)
    at ./../../../dom/base/Element.cpp:3009
#6  0x00007f833527c793 in nsStyledElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/base/nsStyledElement.cpp:208
#7  0x00007f83373d5a47 in nsGenericHTMLElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/html/nsGenericHTMLElement.cpp:482
#8  0x00007f8335320df3 in mozilla::dom::Element::BindToTree (this=0x7f83287a51a0, aContext=..., aParent=...)
    at ./../../../dom/base/Element.cpp:3009
#9  0x00007f833527c793 in nsStyledElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/base/nsStyledElement.cpp:208
#10 0x00007f83373d5a47 in nsGenericHTMLElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/html/nsGenericHTMLElement.cpp:482
#11 0x00007f8335320df3 in mozilla::dom::Element::BindToTree (this=0x7f83287a5080, aContext=..., aParent=...)
    at ./../../../dom/base/Element.cpp:3009
#12 0x00007f833527c793 in nsStyledElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/base/nsStyledElement.cpp:208
#13 0x00007f83373d5a47 in nsGenericHTMLElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/html/nsGenericHTMLElement.cpp:482
#14 0x00007f8335320df3 in mozilla::dom::Element::BindToTree (this=0x7f83287a4f60, aContext=..., aParent=...)
    at ./../../../dom/base/Element.cpp:3009
#15 0x00007f833527c793 in nsStyledElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/base/nsStyledElement.cpp:208
#16 0x00007f83373d5a47 in nsGenericHTMLElement::BindToTree (this=0x7f831d3f49e0, aContext=..., aParent=...)
    at ./../../../dom/html/nsGenericHTMLElement.cpp:482
#17 0x00007f83354c3039 in nsINode::InsertChildBefore
    (this=0x7f83287846f0, aKid=0x7f83287a4f60, aBeforeThis=0x0, aNotify=true, aRv=..., aOldParent=0x0, aMutationEffectOnScript=<optimized out>) at ./../../../dom/base/nsINode.cpp:2177
#18 0x00007f83354c81ae in nsINode::ReplaceOrInsertBefore
    (this=0x7f83287846f0, aReplace=false, aNewChild=0x7f83287a4f60, aRefChild=<optimized out>, aMutationEffectOnScript=MutationEffectOnScript::DropTrustWorthiness, aError=...) at ./../../../dom/base/nsINode.cpp:3561
#19 0x00007f8335aff0be in nsINode::InsertBeforeInternal
    (this=0x7f83287846f0, aNode=..., aChild=0x0, aMutationEffectOnScript=MutationEffectOnScript::DropTrustWorthiness, aError=...) at ../../../dom/base/nsINode.h:2911
#20 nsINode::AppendChildInternal
    (this=0x7f83287846f0, aNode=..., aMutationEffectOnScript=MutationEffectOnScript::DropTrustWorthiness, aError=...)
    at ../../../dom/base/nsINode.h:2925
#21 nsINode::AppendChild (this=0x7f83287846f0, aNode=..., aError=...) at ../../../dom/base/nsINode.h:2919
#22 mozilla::dom::Node_Binding::appendChild (cx_=<optimized out>, obj=Traceback (most recent call last):
  File "/home/emilio/src/moz/firefox-5/js/src/gdb/mozilla/Root.py", line 55, in to_string

Relevant JS stack:

0 Node.prototype.appendChild("[object HTMLUListElement]") ["https://www.jal.co.jp/etc.clientlibs/clientlibs/granite/jquery/granite.min.ed0d934d509c9dab702088c125c92b4f.js":309:29]
    this = [object HTMLDivElement]
1 append/<(elem = "[object HTMLUListElement]", "0") ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":8750:12]
    this = [object HTMLDivElement]
2 domManip(collection = "[object Object]", args = "[object Object]", callback = [function]) ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":8579:14]
3 append("[object Object]") ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":8747:10]
    this = [object Object]
4 wrapAll(html = ""<div class=\"bx-wrapper\"><div class=\"bx-viewport\"></div></div>"") ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":12404:8]
    this = [object Object]
5 wrap/<(i = "0", "[object HTMLUListElement]") ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":12434:19]
    this = [object HTMLUListElement]
6 each(obj = [unavailable], callback = [unavailable]) ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":3042:19]
7 each(callback = [function]) ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":2864:17]
    this = [object Object]
8 wrap(html = ""<div class=\"bx-wrapper\"><div class=\"bx-viewport\"></div></div>"") ["https://www.jal.co.jp/etc.clientlibs/jalaem/ds/core/clientlibs/main.min.af033aa6d8c983ae0aff0cb7606052df.js":12433:15]

So it seems like the DOM operation triggers an image load task which causes .complete to be false, but then another load event doesn't happen.

Comment 9

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2058110 - Don't consider an image incomplete due to a non-alwaysLoad task. r=edgar,#dom-core

This would've also fixed the issue, and I think it's the right thing to
do. It's more annoying to test tho.

Comment 10

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2058110 - Don't queue picture task if pictureness hasn't changed. r=edgar,#dom-core

Matches the UnbindFromTree handling. I have another fix on top which is
a bit more annoying to test, but the test here should cover the broken
website.

Without this relevant-mutations.html fails the picture tests.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/599e5b497192
https://hg.mozilla.org/integration/autoland/rev/849647ec8e10
Don't queue picture task if pictureness hasn't changed. r=edgar,dom-core-reviewers

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/26ee5665f273
https://hg.mozilla.org/integration/autoland/rev/4a669da0a1f9
Don't consider an image incomplete due to a non-alwaysLoad task. r=edgar,dom-core-reviewers

Comment 13

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/61570 for changes under testing/web-platform/tests

Comment 14

[rperta]

https://hg.mozilla.org/mozilla-central/rev/849647ec8e10
https://hg.mozilla.org/mozilla-central/rev/4a669da0a1f9

Comment 15

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected, along with ESR.
:emilio, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta and ESR approvals.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox154 and the ESR status flag(s) to wontfix.

For more information, please visit BugBot documentation.

Comment 16

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 17

[Emilio Cobos Álvarez [:emilio]]

The first patch is low-risk enough IMO.

Comment 18

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2058110 - Don't queue picture task if pictureness hasn't changed.

Matches the UnbindFromTree handling. I have another fix on top which is
a bit more annoying to test, but the test here should cover the broken
website.

Without this relevant-mutations.html fails the picture tests.

Original Revision: https://phabricator.services.mozilla.com/D314436

Comment 19

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined/Reason for urgency: Compat bug with trivial-ish fix.
• Code covered by automated testing?: yes
• Fix verified in Nightly?: yes
• Needs manual QE testing?: yes
• Steps to reproduce for manual QE testing: comment 0
• Risk associated with taking this patch: low
• Explanation of risk level: Matches other browsers and is a one-liner.
• String changes made/needed?: none
• Is Android affected?: yes

Comment 20

[Phabricator Automation]

firefox-esr153 Uplift Approval Request

• User impact if declined/Reason for urgency: Compat bug with trivial-ish fix.
• Code covered by automated testing?: yes
• Fix verified in Nightly?: yes
• Needs manual QE testing?: yes
• Steps to reproduce for manual QE testing: comment 0
• Risk associated with taking this patch: low
• Explanation of risk level: Matches other browsers and is a one-liner.
• String changes made/needed?: none
• Is Android affected?: yes

Comment 21

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2058110 - Don't queue picture task if pictureness hasn't changed.

Matches the UnbindFromTree handling. I have another fix on top which is
a bit more annoying to test, but the test here should cover the broken
website.

Without this relevant-mutations.html fails the picture tests.

Original Revision: https://phabricator.services.mozilla.com/D314436

Comment 22

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/a9cf00f4b207
https://hg.mozilla.org/releases/mozilla-beta/rev/c2cdbf815d58

Comment 23

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr153/rev/caf65490a92b

Comment 24

[Negritas Sergiu, Desktop QA]

Hello! I can confirm that the issue is fixed with firefox 155.0a1(2026-08-03), 154.0b5 and 153.1.0esr on Ubuntu 24.04 and MacOS 15.7.7