[BZ#765627] File copy shouldn't be blocking
Submitted by Tanguy P
Scenario: Copy some files (say, a couple hundred of them) from one side of the dirdiff to the other. Then try to scroll up/down in the dirdiff.
Expected behaviour: We should be able to scroll up/down while the files are being copied. Ideally, we might even want to copy some other files while the others have not finished copying yet (the new files would then be added to a queue of files to be copied).
Actual behaviour: The UI gets completely frozen until the copy operation has finished. Is this a technical limitation of Meld/GTK? Is Meld single-threaded?