I'm actually aware of the problem with session management since last summer, now I've upgraded my stuff to have more KF5-based applications and suprisingly found it still just doesn't work. So I've dived deeper into it this time, reading all the discussion here and last part of bug #341930, both Andreas's change proposals and the thread in the mailing- list.
I likely agree with comment #18 of Andreas and in my point of view it is the following: 1. As a whole it's a massive regression since KDE4 which affects all Qt5 applications, most of which behave correctly as a session clients. Even server parts of both KWin and KSMServer now behave correctly, thanks to Thomas's fixes, I think. But as a whole it just doesn't work at all. 2. This problem is caused by some bug in processing session management messages in Qt, which earlier wasn't a big pain and could be avoided, but due to significant changes in the whole interaction process, in the API etc. now it can't be avoided and lead to (1). 3. There's initial change (https://codereview.qt- project.org/#/c/142232/) by Andreas, which perfectly fixes the problem with any observable problems. It also fixes a fault in the session management protocol implementation for at least two OSs, which is good for Qt itself. 4. There could be potentially affected client applications which: a) were already been ported to/written for Qt5; b) process some valuable data which shouldn't be lost; c) would like to use session management to prevent loss of unsaved data; d) still don't care to follow session management protocol correctly and just exploit old hacks and errors in its implementation, which exist historically, but now is moved to a new place. Unfortunately, this term is a little objectless since it wasn't mentioned any real-life application like this. 5. I completely don't like the proposed way to preserve the compatibility with (4) and make the use case of broken session management client implementation legal and default, but also try to allow proper-written apps to still survive somehow, adding some strange workarounds to Qt as closing all the windows, but not too much, or API properties to enable proper processing of SM messages. To sum it all up, I've applied the patch (3) and have all the session management things back again without any other changes to KDE or whatever, it's already released versions (KF-5.18.0, Plasma-5.5.3, applications-15.12.1). I'll also test Windows behaviour with some toy application. Unless any problems arise, I see no reason why this tiny and simple (and right) fix isn't applied and merged. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to qtbase-opensource-src in Ubuntu. https://bugs.launchpad.net/bugs/1446865 Title: KDE5/Qt5 does not support session restoration Status in KDE Base Workspace: Confirmed Status in Qt: New Status in plasma-workspace package in Ubuntu: Confirmed Status in qtbase-opensource-src package in Ubuntu: Confirmed Bug description: KDE5/Qt5 does not support proper session restoration. ProblemType: Bug DistroRelease: Ubuntu 15.10 To manage notifications about this bug go to: https://bugs.launchpad.net/kdebase-workspace/+bug/1446865/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
