On certain specific applications, left-click dragging on the minimize, maximize, or close buttons on an inactive unfocused background window doesn't make that window active

 * Cinnamon v5.6.5 and v5.6.7 (v5.6.6 was not tested)
 * Mint 21.1

Issue

On certain specific applications (seemingly the programs that do not have a gap between the close button and the top-right corner), when you left-click drag on the minimize, maximize, or close buttons on an inactive unfocused background window, the window you clicked on does not become active and does not move to the foreground.

Steps to reproduce

1. open Nemo
2. open another program such as Backup Tool or xed
3. with Nemo as the active foreground window, position your mouse cursor over the minimize, maximize, or close button for Backup tool and hold down left-click
4. observe how the program window for Backup Tool does not become active and is not moved to the foreground
5. open a program that is known to have a gap between the close button and the top-right corner, such as Archive Manager or Calculator
6. with Nemo as the active foreground window, position your mouse cursor over the minimize, maximize, or close button for Archive Manager and hold down left-click
7. observe how the program window for Archive Manager does become active and is moved to the foreground

Expected behaviour

In step 4, you would have instead expected that Backup Tool would become the active window and get moved to the foreground.

Other information

This issue also occurs on Mint 21.1 MATE, but does not occur on Mint 21.1 Xfce.

Video demonstrating the issue

video.webm

Reproduce the behavior with Nemo in front and Backup Tool or xed behind it, then compare with Archive Manager or Calculator, which do activate when dragged from a window-control button. No source file or test is identified in the report, so trace Cinnamon's window activation and control-button handling from that reproduction. Done means the affected background window becomes active and moves to the foreground, including on MATE, without regressing Xfce behavior.