Every time I click on an entry under 'Recently Saved' for example, Today, Yesterday, This Month, Last Month, dolphin creates a few /tmp/dolphin.something files and doesn't delete them when I close dolphin on click on another entry. I noticed this when I found over 500 files in /tmp/ As a workaround, I set a cronjob that deletes the older ones every hour. Reproducible: Always
I can confirm a similar behavior when browsing the Trash:/ folder and the preview is active. In this case the Dolphin starts to create, inside of /tmp/kde-user dir, a lot of dolphinXXXX.tmp with copies of the files in the trash, and do not delete them. In my laptop, where I generate many files and delete them from dolphin, my trash folder is allowed to store up to 10 GB. And my /tmp partition is 4 GB. So in a few seconds, the kde session starts to fail, and many applications start not to be responding. I need to store in trash just in case some of them are incorrectly deleted. I believe that is something related to thumb preview generation. And as far as I believe this a very useful feature, resources granted to this process (cpu cycles / thread / processes / tmp space) must be somehow tuned in order not to overload the machine.
*** This bug has been marked as a duplicate of bug 208625 ***