multigrid and guis which send mouse inputs to specific windows interact incorrectly with tabline

[Kethku]

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• Operating system/version:
  Windows 10

Actual behaviour

Using a Gui with multigrid extension enabled, and which sends mouse inputs per grid rather than to the base grid, clicking in the top row of a given window will instead send the click to the tabline which may select a different buffer.

Clicking here:

Results in:

Clicking here:

Results in:

Expected behaviour

Clicking in the top row of a window should send the input to that window rather than the tabline.

[Kethku]

If I disable the tabline, or enable the tabline gui extension, this issue goes away. I think that the tabline is hard coded to intercept mouse inputs which have a y of 1 (or 0, I don't remember) which is incorrect when the grid which the mouse input is sent to is not the global one.

[zeertzjq]

Does this bug still exist?

[Kethku]

No it is fixed :) Thanks for the ping