@Pamputt tried to copy and paste text by selecting the text and then clicking with the middle button to paste it at the position of the click (i.e., not at the end of the selected text). The text was pasted where the cursor (still) was. Pamputt expected it to be pasted at the location of the click.
I am using KDE, so I think XFCE is not the guilty. Actually, I would not say that it is not "a very common use case"; I would say it is about linux users but indeed linux users are not so large. It is really common on Lin ux to use select/middle click to copy-paste.
Ack, I thought this was a CodeMirror task (I was linked here from Extension talk:CodeMirror). I've struck my comment above.
I can middleclick paste in VE and NWE (firefox+mint/ubuntu). (woooo!) Sorry for the mistake.
Actually, middle-click to paste works a bit with the visual editor on linux but not the same as in "normal" wikitext or in other any applications that I use on Linux.Here is how it works usually
1/ Select the words you want to copy (by clicking left and moving the mouse for example)
2/ Mouve your mouse to where you want to past the text you copied
3/ Middle-click allows to paste the text at the curosr position
In the visual editor, both steps 1 and 2 are similar. The difference comes from the fact if I click with the middle button, the text will be copied at the position where the cursor was at the end of the copy (or at another position if I clicked in another place), not at the position where the mouse is when I click with the middle button.