Private windows clipboard management

[Trainty]

Hi, new user on the forum, but a long time user of the browser.
A small thing I find rather annoying: the automatic cancellation of the clipboard when closing a private window, as in Firefox until version 28 I believe, it would be better to let the user decide whether clear or maintain the content on exit: the forced cancellation requires a notepad on the side to temporarily keep the content or some other trick to save something from the private session

[Moonchild]

Considering the reason private windows exist, clearing the clipboard is there as an assistive measure to not have anything from the private browsing session be left behind when the browsing window is closed. It's easy enough for people to forget about the clipboard when they browser privately, which can be recovered as a trace after the private session is closed if the clipboard isn't emptied -- making clipboard use in the private session not private...

[Trainty]

Considering the reason private windows exist, clearing the clipboard is there as an assistive measure to not have anything from the private browsing session be left behind when the browsing window is closed. It's easy enough for people to forget about the clipboard when they browser privately, which can be recovered as a trace after the private session is closed if the clipboard isn't emptied -- making clipboard use in the private session not private...

True, but the possibility to select one behaviour or the other would be much better. If the private mode is used as either a) a way to have a temporary clean browser window, without restored tabs or b) to keep sellers tracking at bay when (to buy flight tickets, for example), one might need to use something from the clipboard after the closure of the browser. An option to behave this way would be very useful

[Moonchild]

The main purpose for a Private Browsing window is to have a temporary session that does not save any data from that session once it's closed. That is neither of the two use cases you indicate -- PB windows are there for the user's privacy, not for tracker security nor for some kind of convenience window (you can open a normal browsing window for that).

Private sessions would (naturally) take steps to not save any data from that session so that would logically extend to any clipboard interaction that can be either user-initiated or web-page initiated.

It's fine to make this a user selection, though, but it will be rather low priority for us at this point. Patches are welcome if you want to help add this choice to the browser.