Comment 107 for bug 1265192

@ Bruno, yes I'm talking about the advanced partitioning buttons. It turns out that you are correct. The installer only appears to have deleted the partition (see complied screenshot) but if you click on Quit the partition still exists, so it is possible to quit if you mistakenly think the - button means "shrink" rather than delete. I still contend that's a poor design though because - does not universally = delete, it can also indicate reduce (or shrink/lower).