https://bugs.kde.org/show_bug.cgi?id=316300 fixed in 4.10.2
Could this patch come to 4.10.1? It's a one-liner and fixes a potential data loss.
Backporting is simple enough, but it would have to be added to -r1 for everyone to get the benefit. Committing straight to stable is frowned upon, so we need to figure out an appropriate amount of time before requesting a stabilisation (and if the time until the next KDE SC stabilisation would make the extra work for arch teams worth it).
Not worth a bump straight to stable (if you type rm -rf in the terminal tab, you already prepare shooting yourself in the foot), and anything else will be slower than stabling 4.10.2.
Thanks all. As KDE SC 4.10.2 is now stable on all target arches. This bug is fixed.