Dolphin - Filling the temp folder and breaking boot

I had a thread in the install folder which morphed into a problem about my /tmp folder.

Without pasting the whole thing it comes down to this:

42.1 and KDE, using ext 4. Root partition is 74gig, and temp fills up to breaking point, literally, no boot because / partition is full, in 4-5 days.

Twice now I have had to use a live cd to access system and empty the /tmp folder. As we have been stripped of the ability to cron the problem I set up a systemd solution as noted in another thread to empty /tmp every seven days, except I didn’t get there as the folder filled up in 4, so I changed it one day so we’ll see how that goes.

In the meantime I was interested to find out why /tmp was filling up (64gig) in 3-4 days. I found the culprit I think in Dolphin files that are named (for example) dolphin.A12345.part which, I am told are, temporary stores for transfer/torrent of files and should be sorted once the torrent or transfer has completed. This does not appear to be happening as these files remain long after the event. They remain named as above, and they are what are filling up /tmp, and there are often multiple copies of the same file, not alwasy the whole thing by large parts of it.

So any ideas as to what is happening and why Dolphin is not doing what it should, whatever that is, with these files. I am not sure what Dolphin should do but IMO, storing in/tmp while a transfer/torrent is in progress I can understand, but on completion they should be deleted automatically.

There are bug reports about dolphin filling up /tmp.

But .part files are unfinished downloads/transfers. I think its on purpose that they don’t get deleted (of course they should be when the transfer is finished, otherwise it’s a bug).
Although they shouldn’t be created in /tmp in the first place I suppose. That could lead to problems when /tmp is a tmpfs (stored in RAM) and you download/copy/move large files.

The .part files are zombies in most case, the files have well and truly finished transferring. So it looks like this is a bug.

Can you find a simple and reliable way to reproduce this?
E.g. “Open a FTP folder and copy a file to your local hard disk”.

That’s necessary for a good bug report/being able to fix it.

It’s likely not a bug in dolphin itself, but rather KIO or one particular slave.