restore terminal title on exit (xterm)

[gfrlv]

issue #11909

On xterm, there is a terminal "stack" that allows to save and then restore the current terminal title. It allows to reset title to the original value on exit in case it was changed.

[gfrlv]

Checked the master branch on windows 7, the title is restored on exit, so it seems that the problem shows on xterm only.

[Carreau]

I don't have any objections;

I remember some discussion about that some time ago; and I believe this may garbled the output on some other kind of terminal.

Note that I believe the logic might be perfect in all the case as set_term_title might be called a second time if something change the internal title string. In which case another title is pushed; but only one will be pop'ed at exit.

I believe in the long run we might want to have with title() context manager to make sure we do things properly.

[gfrlv]

I remember some discussion about that some time ago; and I believe this may garbled the output on some other kind of terminal.

Do you have any pointers to that discussion? If restoring the title messes things up, chances are setting the title does too, perhaps we can do something special for such systems.

I believe in the long run we might want to have with title()

Seems sensible, I'll look how to best do it. Is this a theoretical concern, or are there cases where we set the title multiple times?

[Carreau]

Do you have any pointers to that discussion?
No, just in my memory, I found #10856 as well, but I coudl swear there is more.

Seems sensible, I'll look how to best do it.

That will probably be a lot of refactor; so loooong term.

Or are there cases where we set the title multiple times?

With current code base I believe the title can be set multiple times. But with the proper context manager we should be able to count how many time it was changed from within the context manager and pop the appropriate number of time.

It may even be a feature we want in prompt_toolkit