Comment 6 for bug 79289

User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1) Gecko/20061222 Firefox/2.0.0.1
Build Identifier: version 1.5.0.9 (20061223)

Starting with gtk 2.10.7, drags are canceled when the toolkit-private drag widget
is grab-shadowed by another gtk_grab_add call in the application. This is a
necessary fix to avoid "stuck drag" situations when a modal dialog pops up while
a drag is in progress.

Unfortunately, the mozilla dnd implementation does just that - it calls gtk_grab_add in the nsDragService::GetTargetDragData method. This causes
drags of mesages from the message list to the folder tree in thunderbird
to fail with gtk 2.10.7.

Fortunately, the gtk_grab_add in nsDragService::GetTargetDragData doesn't
seem to have any real purpose - at least the nsDragService code doesn't
make any use of the grabbing, and just removing the grab_add/grab_remove
calls in that function makes dnd work again in thunderbird.

Reproducible: Always

Steps to Reproduce:
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