Comment 2 for bug 392043

This issue is general one, and affects every GUI app.

I experienced the same usability problems with Thunderbird:

Goal: Drag'n'Drop and old email as an attachment to a new one.

How it should be done:
* press "New" to create new email, write there what you need.
* go to main thunderbird window
* search needed old email there, press and hold mouse on it
* if new-email-window is visible by any of it's sides or corners, then move mouse on it (dragging old email with it)
** it should change the focus on new-email-window
** move mouse to attachment's area (top-right corner) and drop the dragging object.
* if new-email-window is hidden (fully covered by other windows), then press Alt-Tab several times to find it (still pressing the mouse button)
** when window is found, it gains a focus
** move mouse to needed area and drop the object.

Currently both of ways (give focus by alt-tab or mouse move with pressed button) are not working now.

The only workaround I found is to mark new-email-window always-on-top for the time range when I need to drag-and-drop object on it.

I added Thunderbird project to this bug, because the usage pattern I described is a quite common for me, and I need this resolved!
But as jac3n described, it affects almost every application.

Thanks.