Found in

• Firefox Nightly 125.0a1

Affected versions

• Firefox Nightly 125.0a1

Tested platforms

• Affected platforms: macOS 11.6

Preconditions

• Install DE Firefox build
• Use DE VPN
• browser.search.region = DE
• extensions.formautofill.addresses.experiments.enabled - true
• extensions.formautofill.addresses.supportedCountries = DE
• extensions.formautofill.addresses.capture.requiredFields = empty

Steps to reproduce

1. Reach the address form on https://www.hessnatur.com
2. Click on "Name" field
3. Select any of the options for the dropdown
4. Right click on any of the fields and choose "Clear autofill form"
5. Repeat steps from above for the rest of the fields

Expected result

• Form autofill/preview/clear should be applied on eligible fields.

Actual result

• Form autofill/preview/clear are only applied on the selected field.

Regression range

• N/A

Additional notes

• Not reproducible on Chrome.
• Fathom: https://drive.google.com/file/d/1mQ6nGSnXvCAoWUyAHvoJjwR2cXbLqYWx/view?usp=sharing

All the fields seem to filled in except for the street which is not being detected.

The issue here is that <label> elements are not connected to the input element -- they have no 'for' attribute, and the street's formfield name is just 'line1' so it does not matched.

The solution here is probably to guess that the a label without a 'for' attribute that otherwise doesn't match is meant to correspond to a neighboring input field. In this site here, the input immediately precedes the label.

This is a somewhat limited fix and only handles form controls that are adjacent to the label, and does not handle those that might be a nested styled element.

https://hg.mozilla.org/mozilla-central/rev/b7cd8cf2eac0

Verified as Fixed on MacOS 14, Windows 11 and Ubuntu 22.04.