Failing to drag tab for split window when native sidebar is on the right

[sporocyst]

Captchas

• [x] I have read the instructions.
• [x] I have searched existing issues and avoided creating duplicates.
• [x] I am not filing an enhancement request.
• [x] I have checked that this issue cannot be reproduced on Mozilla Firefox.
• [x] I have checked that this issue cannot be reproduced once I removed all my Mods and Custom CSS.

What happened?

Normally, when drag a tab to the right sdie of current page to mak split window, we can see it like:

But with native sidebar panel enabled on right side, it will become this:

Here, the browser will try to put tab to right side of sidebar(in this case, my bookmark tree) and end up failing to make split window

Version

1.10.3b

What platform are you seeing the problem on?

Windows - x64

What component is this issue related to?

Split View

Relevant log output if applicable

[Propheticus]

The same happens when the sidebar is on the left and you try to drag a site to the left of the current to split them. The dragged page then get put between the tab bar (if left) and the sidebar, failing to make the split view.

Bonus issue, as long as the sidebar is open and you are in a split view, the split can't be dragged and repositioned. Without a sidebar open: With a sidebar open:

[Propheticus]

I can recreate this in the latest twilight (Version 1.11.2t Build ID 20250411093359)

With the native sidebar (bookmarks sidebar for example) open;

• When the native sidebar is on the left, you cannot drag a site to the left of the current site to split
• When the native sidebar is on the right, you cannot drag a site to the right of the current site to split

The bonus issue above is also still valid.

[SO9010]

https://github.com/user-attachments/assets/ab8abbc2-9eb8-43e6-933a-41a3186f9f4a

Here is a screen recording for more detail on how the bug looks visually!

[SO9010]

Also all of the drop locations are wrong! Also this is an issue in linux too!

https://github.com/user-attachments/assets/5c7834f5-2137-4958-89e0-7ea4a58d9879

[SO9010]

Just to note it somewhere where it may be useful, you can resize, just the splitter will be in the place where it would be if the sidebar wasn't there. I think the issue is coming from the fact that zen-splitview-overlay-wrapper takes up the all of the tabs place inc. sidebars.

Edit: This part is an easy fix, I have done it, I also noticed that the glance buttons were off, but I fixed that too as that is a related issue, I think that it is this issue #7027. I'm still working on fixing the initial bug, that is proving a lot more challenging...

[dosubot[bot]]

Hi, @sporocyst. I'm Dosu, and I'm helping the desktop team manage their backlog. I'm marking this issue as stale.

Issue Summary:

• Original issue: Dragging tabs to create a split window with the native sidebar enabled results in incorrect tab placement.
• @Propheticus confirms the issue occurs on both sides of the sidebar and notes split views cannot be repositioned with the sidebar open.
• @SO9010 provides visual evidence, mentions the issue affects Linux, and suggests it may be related to zen-splitview-overlay-wrapper's handling of space.
• @SO9010 has made progress on related issues but finds the main bug challenging to resolve.

Next Steps:

• Please let me know if this issue is still relevant to the latest version of the desktop repository by commenting here.
• If no updates are provided, the issue will be automatically closed in 7 days.

Thank you for your understanding and contribution!

[sporocyst]

Issue exists on 1.13.1b (Firefox 139.0.4)

[dosubot[bot]]

Hi, @sporocyst. I'm Dosu, and I'm helping the desktop team manage their backlog. I'm marking this issue as stale.

Issue Summary:

• The issue involves incorrect tab placement when dragging tabs to create a split window with the native sidebar enabled.
• @Propheticus confirmed the issue occurs on both sides of the sidebar and noted split views cannot be repositioned with the sidebar open.
• @SO9010 provided visual evidence, mentioned the issue affects Linux, and suggested it may relate to the zen-splitview-overlay-wrapper's handling of space.
• You confirmed the issue persists in version 1.13.1b.

Next Steps:

• Please let us know if this issue is still relevant to the latest version of the desktop repository by commenting here.
• If there is no further activity, this issue will be automatically closed in 7 days.

Thank you for your understanding and contribution!

[sporocyst]

Issue exists on 1.14.5b (Firefox 140.0.4)

[SO9010]

Alright should be solved soon, I have submitted a PR!