1676169 - An empty placeholder is created when dragging a topsite over a sponsored one

Status: VERIFIED FIXED

(Firefox :: Top Sites, defect, P1)

Description

[Petruta Horea [:phorea], PTO until 8/22/25]

[Suggested Severity:]

S4

[Description:]

Trying to move the first unpinned topsite over a sponsored tile will create an empty placeholder.

[Environment:]

Windows 10, Mac OSX 10.15
83.0b10-trybuild

[Preconditions:]

Position 1 and Position 2 have sponsored top sites.

[Steps:]

1. Download and install RO localized Firefox.
2. Create an user.js and set: browser.topsites.useRemoteSetting = true and browser.search.region to "RO", connecting to the staging main-preview.
3. Start the browser with the predefined profile.
4. Open a new about:preferences#home and set topsites to be shown on 4 rows.
5. Open a new tab.
6. Observe the topsites section.
7. Drag the third topsite over the first one (sponsored)

[Actual Result:]

• An empty placeholder is created on the third position.
• If any other topsite is moved over the first position (over a sponsored tile), it will first be placed on the first unlocked position (3rd position in this scenario) and redoing the operation will create the empty placeholder.

[Expected Result:]

The topsite is placed back to its initial position (3rd in this case). There are no empty placeholders created.

[Note:]

Screenshot: https://drive.google.com/file/d/1mK-c4ahisPDgMMoSXA7_MCkWdEBvMq7Q/view?usp=sharing

Comment 1

[Dão Gottwald [:dao]]

Attachment: Bug 1676169 - Completely disallow dropping on sponsored tiles. r=mikedeboer

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f3af31c0c275
Completely disallow dropping on sponsored tiles. r=mikedeboer

Comment 3

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/f3af31c0c275

Comment 4

[Petruta Horea [:phorea], PTO until 8/22/25]

Verified as fixed using latest Nightly 84.0a1 under Win 10 64-bit and Ubuntu 18.04 64-bit.