Pcmanfm 'ghost' file move with drag and drop

[Botspot]

Not sure if this is a new issue due to Wayland on Bookworm, but this is a bit of an edge case that I somehow keep encountering, regardless of how unusually specific the replication steps seem to be.

To reproduce:

1. Use Wayland on PiOS Bookworm (This may not be necessary)
2. Open pcmanfm and select a file in a folder like ~/Downloads. Click and drag the file past the edge of the pcmanfm window, then drag it back. The file has not moved.
3. Now go to a different folder, like ~/Documents. Click and drag a file past the edge of the pcmanfm window, then drag it back.
4. The second file has not been moved either, but you will notice that the first file, that was originally located in Downloads, has now been moved to Documents.

I have lost multiple files from this bug, and for a while suspected filesystem corruption as the cause for when my files started vanishing.

If anyone here cannot reproduce this using my steps provided, it could be due to some pcmanfm preferences I set. If this ends up being hard to reproduce, then I can try to find a spare sd card to reproduce this on a clean install, though I am fairly sure that this occurs across the board.

[ghollingworth]

I can reproduce that here as well...

[spl237]

OK, I've found the problem - the file manager caches source file data, and the rules by which this cache is cleared and updated don't handle various situations where a drag and drop does not complete.

I've got a fix - we'll do some testing internally before we push it out.