I tried and managed to reproduce your issue!Seems like the custom shortcut icon trick only works, when having the 'Combine taskbar buttons and labels' setting (a.k.a. taskbar grouping) set to 'always'. When showing labels in the taskbar like in your ...
Huh, that seems odd to me. Are you sure you got the right shortcut file?For reference, Thunderbird on Windows (don't mind the sharp corners) running from a shortcut with a custom icon:
If you are referring to the taskbar icon and are using thunderbird on windows, you can easily change the icon of the thunderbird shortcut yourself, causing the program its pointing to to inherit your custom icon ( only when run by the shortcut ).
I think this feature already exists, at least in the download drop-down menu.Clicking an active download in the list marks it to be opened once fully downloaded:Afaik this is currently not possible in the downloads page, and it would be nice for this...
