2035512 - Inserting mouse cursor caret in address bar at specific location no longer works when clicking near top/bottom edges of box (insertable height does not match visual height)

Status: VERIFIED FIXED

(Firefox :: Address Bar, defect, P3)

Description

[Kestrel]

Attachment: Caret insertion fails near address bar edges

STR:

1. Start latest Nightly 152.0a1 on Ubuntu 26.04.
2. Move the mouse cursor into the address bar above/below where there is text.
3. When the cursor icon first changes to an "I" to indicate insertion, left-click and drag to make a selection.

Expected:
Caret inserted at mouse cursor position like before.

Actual:
Caret inserted at end of address when clicking on bottom edge or at beginning of address when clicking on top edge.

The deadzone around the edges of the address bar where caret insertion fails despite the icon showing "I" is 5px which is 36% of the clickable height. The user must be careful to click directly over text for caret insertion to work at the cursor location like before.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=02376ed8674012d2bd575682466cc9177039adb9&tochange=a77a08b9be8a059936afa68f259adb86823bb75f

Regressed by Bug 2031757.

Comment 1

[BugBot [:suhaib / :marco]]

:emilio, since you are the author of the regressor, bug 2031757, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Emilio Cobos Álvarez [:emilio]]

This is kind of expected because the editable element no longer covers the whole padding area...

Comment 3

[Emilio Cobos Álvarez [:emilio]]

I guess a potential way of addressing this for the urlbar could be to bump up the line-height.

Comment 4

[Maxx Crawford [:maxx]]

Hey Emilo! I'm the Engineering REO for Fx151.

Is this bug something that we can expect a patch/uplift for? Specifically, your comment regarding that this may expected behavior, I wasn't sure if this was more of a WONTFIX.

Thank you!

Comment 5

[Emilio Cobos Álvarez [:emilio]]

Yeah I don't see how to easily fix it other than doing something like comment 3 (which works on the urlbar but not on the smartbar etc). This feels very low severity but lmk if you disagree.

Comment 6

[Kestrel]

When I first encountered this, it wasn't clear why it was happening. Insertion failed randomly and it took me some time to figure out I wasn't clicking in the right spot. It is relatively easy to account for once you understand how it works but many people will have a similar confusing discovery process and some will never fully understand it. Users expect the border and cursor icon to define the interactive area but that is no longer the case.

The smaller and less forgiving interactive area also makes the address bar less accessible, requiring more precise cursor placement. The address bar is very prominent and should be as frictionless as possible.

Chrome has the expected behavior.

Comment 7

[Kestrel]

This was partially fixed but has regressed again in latest Nightly. The cursor icon changed to a caret only in the insertable areas which avoided confusion but now it has gone back to the full height, including areas that are not insertable.

Partial fix window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=14b0bb51437f40a70414998f8bdc96c3ae09cf23&tochange=baacfcca6a956c09ebf7b735290133eed268df8c

Partially fixed by Bug 2039721.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=3f9d84a97b5989975cacbfd4ef1f7a6a4842fbaa&tochange=1f793ac428db458797324746e0964d708f9cb926

Regressed by Bug 2050821.

Comment 8

[Marco Bonardo [:mak]]

let's investigate this as part of Nova follow-ons

Comment 9

[Drew Willcoxon :adw]

I agree with comment 6 and think we should fix this for Nova.

Comment 10

[Drew Willcoxon :adw]

(In reply to Drew Willcoxon :adw (Away July 17–July 24) from comment #9)

I agree with comment 6 and think we should fix this for Nova.

Or at least revert it back to before bug 2050821 regressed it again, but we need to be careful not to reintroduce the problem that bug 2050821 was addressing.

Comment 11

[Daisuke Akatsuka (:daisuke)]

I tried a few things, and it seems that increasing line-height works well, as Emilio suggested. I will make the patch.

Comment 12

[Daisuke Akatsuka (:daisuke)]

Attachment: Bug 2035512 - Increase the urlbar input's line-height so the caret can be placed anywhere

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/0c8a121f4e29
https://hg.mozilla.org/integration/autoland/rev/b61d1b06ff39
Increase the urlbar input's line-height so the caret can be placed anywhere r=desktop-theme-reviewers,urlbar-reviewers,dao

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/54009ff250a4
https://hg.mozilla.org/integration/autoland/rev/a24092a99e09
Revert "Bug 2035512 - Increase the urlbar input's line-height so the caret can be placed anywhere r=desktop-theme-reviewers,urlbar-reviewers,dao" for causing wpt failures in anchor-scroll-position-try-016.html.

Comment 15

[Serban Stanca [:SerbanS]]

Reverted this because it was causing wpt failures in anchor-scroll-position-try-016.html.

• Revert link
• Push with failures
• Failure Log
• Failure line: TEST-UNEXPECTED-PASS | /css/css-anchor-position/anchor-scroll-position-try-016.html | Initially, anchored is at top left position - expected FAIL

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/9f4bdbdd64a5
https://hg.mozilla.org/integration/autoland/rev/2a566d62ef69
Increase the urlbar input's line-height so the caret can be placed anywhere r=desktop-theme-reviewers,urlbar-reviewers,dao

Comment 17

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/2a566d62ef69

Comment 18

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected, along with ESR.
:daisuke, 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 19

[Daisuke Akatsuka (:daisuke)]

Attachment: Bug 2035512 - Increase the urlbar input's line-height so the caret can be placed anywhere

Original Revision: https://phabricator.services.mozilla.com/D313373

Comment 20

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined/Reason for urgency: User can't put the caret position correctly by clicking at the edge of the urlbar.
• Code covered by automated testing?: no
• Fix verified in Nightly?: yes
• Needs manual QE testing?: no
• Steps to reproduce for manual QE testing:
• Risk associated with taking this patch: low
• Explanation of risk level: The code changes only CSS line-height.
• String changes made/needed?: None
• Is Android affected?: unknown

Comment 21

[Daisuke Akatsuka (:daisuke)]

Attachment: Bug 2035512 - Increase the urlbar input's line-height so the caret can be placed anywhere

Original Revision: https://phabricator.services.mozilla.com/D313373

Comment 22

[Phabricator Automation]

firefox-esr153 Uplift Approval Request

• User impact if declined/Reason for urgency: User can't put the caret position correctly by clicking at the edge of the urlbar.
• Code covered by automated testing?: no
• Fix verified in Nightly?: yes
• Needs manual QE testing?: no
• Steps to reproduce for manual QE testing:
• Risk associated with taking this patch: low
• Explanation of risk level: The code changes only CSS line-height.
• String changes made/needed?: None
• Is Android affected?: unknown

Comment 23

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/17356ff7e2bf
https://hg.mozilla.org/releases/mozilla-beta/rev/a89f41bbbd9a

Comment 24

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr153/rev/87af08a4401a

Comment 25

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr153/rev/33a1ed95bfe6

Comment 26

[Dianna Smith [:diannaS]]

:daisuke backed out of esr153 due to bc failures and wpt failures

Comment 27

[Daisuke Akatsuka (:daisuke)]

We wanted to uplift this fix to the ESR, but it might make another regression, we decided to stop uplifting. Thanks!

Comment 28

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Reproducible on a 2026-04-28 Firefox Nightly build on Ubuntu 22.

Verified as fixed on Firefox Nightly 155.0a1 and Firefox 154.0b9 on Ubuntu 22, macOS 13, Windows 10.