Horizontal windows tiling automatically reverts to vertical windows tiling

[vladtarko]

Distribution: Pop!_OS version 21.04

Related to: The windows self-tiling system. This occurs when 'Tile Windows' is ON.

Issue/Bug Description: Windows that are set by the user to be one below the other (horizontal tiling), automatically switch to vertical tiling (one left, other right) under certain conditions.

Steps to reproduce:

1. Open two windows, e.g. two terminals.
2. Drag one below the other, so they are tiled horizontally (one top of the screen, the other bottom).
3. Open a third window.
4. Close the third window.

Expected behavior: The first two windows should preserve the horizontal tiling (one below the other). Instead, they automatically switch to vertical (one left side, one right side).

Other notes: One use case is on a laptop having a reference manager like Zotero at the bottom of the screen, and the main text editor at the top. After opening a pdf or a webpage from Zotero, and then closing the pdf/browser, Zotero should not switch to the right side of the screen, but should remain at the bottom as it was originally set.

[matthewtraughber]

Confirmed this issue for myself with the (for now) latest pull of master.