https://bugs.winehq.org/show_bug.cgi?id=55179
--- Comment #15 from Pascal Mons pascal_mons@hotmail.com --- Thank you for your feedback. However I would like to stress that it's not "dragging and dropping onto the center of the window", but instead 'anywhere' within the application's window, except for the title bar. Then the application receives the mouse position (x, y) and deals with it accordingly.
I just did a check on WineHQ version 7.0.2 by installing these packages over the current ones from version 8.0.2 (thus downgrading). It's easy and there is no need to re-install any wine application.
dpkg: warning: downgrading winehq-stable from 8.0.1~focal-1 to 7.0.2~focal-1 (Reading database ... 1160236 files and directories currently installed.) Preparing to unpack winehq-stable_7.0.2~focal-1_amd64.deb ... Unpacking winehq-stable (7.0.2~focal-1) over (8.0.1~focal-1) ... dpkg: warning: downgrading wine-stable from 8.0.1~focal-1 to 7.0.2~focal-1 Preparing to unpack wine-stable_7.0.2~focal-1_amd64.deb ... Unpacking wine-stable (7.0.2~focal-1) over (8.0.1~focal-1) ... dpkg: warning: downgrading wine-stable-amd64 from 8.0.1~focal-1 to 7.0.2~focal-1 Preparing to unpack wine-stable-amd64_7.0.2~focal-1_amd64.deb ... Unpacking wine-stable-amd64 (7.0.2~focal-1) over (8.0.1~focal-1) ... dpkg: warning: downgrading wine-stable-i386:i386 from 8.0.1~focal-1 to 7.0.2~focal-1 Preparing to unpack wine-stable-i386_7.0.2~focal-1_i386.deb ...
I believe you can do the test yourself, as a white + appears on a background accent color circle (blue for me), close to the square / rectangle representing the data file, as long as the mouse is inside the application's window [anywhere].
So, I can confirm that any data file dropped within the application's window space [except for the title bar] is opened by MapSource, on WineHQ 7.0.2. While on version 8.0.2 it's only working if dragged & dropped on the menu and tools bar.
That's the regression which isn't in compliance with the design specifications of the Drag & Drop capability within UNIX and Windows systems.
So, obviously something has changed between WineHQ version 7 and version 8. The goal is to identify what has changed.