2064781 - Autofill for Addresses and Names Fails with Some HTML Forms Using Firefox 154.0

Status: UNCONFIRMED

(Toolkit :: Form Autofill, defect)

Description

[Dale Feinstein]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:154.0) Gecko/20100101 Firefox/154.0

Steps to reproduce:

1. Visit https://www.pch.com/pages/free-alternative-method-of-entry .

2. Click in the "First Name*" field.

Actual results:

The cursor blinks in the "First Name*" field, allowing the user to enter text. However, no option to autofill the form is presented.

Expected results:

Firefox should have presented the option to autofill the form with name, email address, and phone number.

With the previous version of Firefox, version 153, HTML form Autofill functioned properly.

Other Firefox 154.0 users are reporting similar problems with HTML form Autofill - https://www.reddit.com/r/firefox/comments/1vro8hl/firefox_1540/ .

Comment 1

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Toolkit::Form Autofill' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Dimi Lee [:dimi]]

HI Ailea, could you help test if you can reproduce this issue with Fx 154 on Windows? Thanks

Comment 3

[Dimi Lee [:dimi]]

Hi Dale, thank you for reporting this issue!
One question: besides the reported site, are you able to autofill on other sites?
For example, are you able to autofill the Address Sign-Up form on this page?

Also, could you help share the information in your about:support? Here are the steps:

1. Type about:support in the address bar, press enter.
2. Click Copy raw data to clipboard.
3. Come back to this bug, click the Attach new file button above your first comment.
4. Paste the content from your clipboard, add a description and hit Submit at the bottom.

Really appreciate for your help!

Comment 4

[Dale Feinstein]

On https://dimidl.github.io/signup/test.html, Firefox only completes the Email, Phone Number, and Zip Code fields when clicking in each form field and then selecting the appropriate text in the drop down menu. However, Firefox no longer completes the entire form in one click as it did in previous versions. In previous versions of Firefox, form fields that could be autofilled would appear with a yellow background; however, this yellow background in form fields no longer appears in Firefox 154.

Comment 5

[Dale Feinstein]

Attachment: Firefox 154 about:support raw data; OS: Windows 11 25H2 - OS Build: 26200.9168

Comment 6

[Dimi Lee [:dimi]]

Hi Dale, Really appreciate for the you help, that helps a lot!
Could you help test the two sites (https://dimidl.github.io/signup/test.html and https://www.pch.com/pages/free-alternative-method-of-entry) again with our developer tool?

Here are the step:

1. Install the autofill developer tool by clicking the autofill-devtools.xpi in this page
2. Navigate to the page with the form and open the Web Developer Tools
3. In the tool, you should see "Autofill" in the toolbar (see the attachment)
4. Navigate to the Autofill Panel
5. Check the "Show Unknown" checkbox
6. Click the "Click to inspect" button
7. Take a screen and then upload the screenshot

Thank you!

Comment 7

[Dimi Lee [:dimi]]

Attachment: autofill developer tool.png

Comment 8

[Dale Feinstein]

Attachment: dimidl form test screenshot

Comment 9

[Dale Feinstein]

Attachment: pch form test screenshot

Comment 10

[Dimi Lee [:dimi]]

That is super helpful, thanks!

Comment 11

[Dimi Lee [:dimi]]

Attachment: WIP: Bug 2064781 - Pin the form autofill ML engines to fp32

Note. this is meant to only for dicsussing the root cause, not for a fix.

On some machines the ML field classifier returns other for nearly every
address field and assigns a single dominant label (address-level2) to the
rest. No address section is then built, so no autofill dropdown or field
highlight is offered.

The Remote Settings record for formfill-encoder carries no dtype field.
When dtype is unset, ONNXPipeline falls back to "q8", so the encoder runs
int8-quantized while the head it feeds runs fp32.

int8 matmul is not numerically consistent across CPU backends: the x86 AVX2
path without VNNI saturates where ARM does not, so the encoder's pooled
embeddings differ by architecture. The head consumes those embeddings
directly, and the windowed feature row amplifies the difference by including
the cur - prev and cur - next terms. Off-distribution input collapses the
head onto one label. This is why an identical build with identical model
revisions classifies the same form correctly on arm64 and incorrectly on
x86_64.

Pin dtype explicitly on both engine configs instead of inheriting it. Caller
options override the Remote Settings record in
MLEngineChild.initializeInferenceEngine, so the encoder precision no longer
depends on a field that is currently absent. The head already resolves to fp32
from Remote Settings; pinning it as well guards against the same omission,
since model_quantized.onnx does not exist in that repository and a q8
fallback would fail engine creation outright.

Two trade-offs worth noting. The fp32 encoder artifact is 44.7 MB against
9.8 MB for the quantized one, so this costs a larger one-time download and
slower inference. And re-exporting the encoder with reduce_range would keep
the smaller artifact while fixing the x86 path, which is the better long-term
fix.

Comment 12

[Giorgia Nichita, Release Desktop QA]

Attachment: Autofill fails.gif

We tested both sites in Firefox 154.0 on Windows 10.

• https://www.pch.com/pages/free-alternative-method-of-entry: Autofill works initially. However, after closing the page and reopening it in another tab, the Autofill option no longer appears.
• https://dimidl.github.io/signup/test.html: The Autofill option does not appear.
  We also tested on a Mac 15 ARM and a Mac 11 and we could not reproduce the issue on either site on either Mac.

Please let us know if there is anything else we can do to help investigate this issue.

Comment 13

[Dianna Smith [:diannaS]]

:Dale We've rolled out a mitigation for this issue, could you confirm the issue is still occurring after restarting the browser?

Comment 14

[Dale Feinstein]

(In reply to Dianna Smith [:diannaS] from comment #13)

:Dale We've rolled out a mitigation for this issue, could you confirm the issue is still occurring after restarting the browser?

After restarting Firefox, the issue is no longer occurring after the mitigation. Autofill can now be successfully used to complete the HTML forms at both https://www.pch.com/pages/free-alternative-method-of-entry and https://dimidl.github.io/signup/test.html .

Thank you.

Comment 15

[Michael]

Can confirm version 154 has broken autofill. Last version did not have this problem.

Comment 16

[Dale Feinstein]

(In reply to Michael from comment #15)

Can confirm version 154 has broken autofill. Last version did not have this problem.

A mitigation has been rolled out. You may wish to restart Firefox to determine if the Autofill problem is resolved for you.

Comment 17

[Michael]

Firefox is up to date. What mitigation where/how?

Comment 18

[Michael]

(In reply to Dale Feinstein from comment #16)

(In reply to Michael from comment #15)

Can confirm version 154 has broken autofill. Last version did not have this problem.

A mitigation has been rolled out. You may wish to restart Firefox to determine if the Autofill problem is resolved for you.

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