A flaw has been identified in the way Apple's operating system Leopard moves files between storage volumes which deletes the source file if the transfer is disrupted.
Tom Karpik, a computer science student at the British Columbia Institute of Technology, says he has identified a bug in Leopard that can cause data loss at the source file while moving files to another hard drive.
If the source of the files crash or is disconnected from the network while the move is under way, the contents of the file completely disappear from the source machine, leaving the user with only with the files already copied to the destination machine.
The problem is related specifically to moving files -- as opposed to copying them -- which is considered a risky method of transporting files since the user acknowledges they want that file deleted from the source machine once the operation is completed. The default setting in Leopard also is to "copy" the file from source to destination when the icon is dragged across the screen -- bypassing the default requires a user to hold down the Command key while dragging the icon.
Commenters on Karpik's blog, Slashdot, and others like Daring Fireball's John Gruber point out that users are asking for trouble if they opt to "move" files rather than copy them -- if the user wants the file deleted from the source machine, they should manually delete it after the transfer is complete.
But Karpik's point is that Leopard should not delete the source data until it has verified that the transfer was successfully completed.
"Windows behaves differently in that it never deletes the source unless everything has been completely copied to the destination. This is just sane, to-be-expected behaviour," he wrote in an e-mail in response to asking for clarification on a couple of his findings.
The problem may not just be isolated to Leopard however. Some commenters on Karpik's blog said this issue has existed since Panther (Mac OS X 10.3).
ZDNet Australia's sister site CNet News has contacted Apple to ask if it had identified this as a bug or problem, however Apple is yet to respond.












Isure does seem like there's a lot of piling on going on with Apple's new Leopard. I just wonder if some of this isn't of Microsoft's orchestrating, considering the pounding their latest OS, Vista has taken. Something to consider, eh?