Bug 337353

Are there any other KF5 applications with the same bug? It could be a problem with KMainWindow/KConfig integration.

@christoph

this looks to be the case with Konsole and Kate as well. But not with Quassel IRC for example. anything else i could/should test?

Confirmed also with Okteta, so it's definitively not a Dolphin problem.

I've been doing some investigation into this.

It looks like setting a central widget (setCentralWidget()) on KXmlGuiWindow breaks restoring the size because of some code in QWidget.

I'll see where I can get and will keep this bug updated.

I hate to do a +1, but I also see this on many qml based system configuration screens from systemsettings.

*** Bug 338212 has been marked as a duplicate of this bug. ***

Is there any update on this bug ??  

More and more programs are being ported to Frameworks, but all suffer from the same issue. And this becomes slowly quite annoying.

yep i can confirm that this is still an issue. and as long as it's not fixed i'll stay with kde4 (which is very awesome and i am sure kde devs will bring kde plasma next to at least that point if not even better)

This is a bug in Qt -- https://bugreports.qt-project.org/browse/QTBUG-40584

You might want to ping it there, that would be bigger help actually ;)

Hi Martin,

Wasn't aware that there was a QTBUG for it :)  Added a comment and a vote.

Thanks

Possible workaround (untested) - adapted from https://git.reviewboard.kde.org/r/119594/

diff --git a/src/kmainwindow.cpp b/src/kmainwindow.cpp
index e273a76..be95a42 100644
--- a/src/kmainwindow.cpp
+++ b/src/kmainwindow.cpp
@@ -609,6 +609,10 @@ void KMainWindow::applyMainWindowSettings(const KConfigGroup &cg)
 
     if (!d->sizeApplied) {
         KWindowConfig::restoreWindowSize(windowHandle(), cg);
+        // NOTICE: QWindow::setGeometry() does NOT impact the backing QWidget geometry even if the platform
+        // window was created -> QTBUG-40584. We therefore copy the size here.
+        // TODO: remove once this was resolved in QWidget QPA
+        resize(windowHandle()->size());
         d->sizeApplied = true;
     }

looks like this has some effect; with dolphin at least, size is now saved. however the patch triggers kwrite segfault (this is with the Qt patch applied):

Thread 1 (Thread 0x7ffff7f4e7c0 (LWP 19656)):
#0  0x00007ffff619a098 in KMainWindow::applyMainWindowSettings(KConfigGroup const&) (this=this@entry=0x6a34a0, cg=...)
    at /usr/src/debug/kxmlgui-5.1.0git/src/kmainwindow.cpp:616
#1  0x00007ffff61d2e72 in KXmlGuiWindow::applyMainWindowSettings(KConfigGroup const&) (this=0x6a34a0, config=...)
    at /usr/src/debug/kxmlgui-5.1.0git/src/kxmlguiwindow.cpp:374
#2  0x00007ffff619a44c in KMainWindow::setAutoSaveSettings(QString const&, bool) (this=0x6a34a0, groupName=..., saveWindowSize=<optimized out>) at /usr/src/debug/kxmlgui-5.1.0git/src/kmainwindow.cpp:705
#3  0x00007ffff7bd3fc8 in  () at /usr/lib64/libkdeinit5_kwrite.so
#4  0x00007ffff7bd0f87 in kdemain () at /usr/lib64/libkdeinit5_kwrite.so
#5  0x00007ffff783db05 in __libc_start_main () at /lib64/libc.so.6
#6  0x00000000004007ee in _start ()

Thanks for testing.
Means applyMainWindowSettings() is also run w/o a real window (ie. restoreWindowSize() is noop)

Adjusted patch:

diff --git a/src/kmainwindow.cpp b/src/kmainwindow.cpp
index e273a76..d7f7442 100644
--- a/src/kmainwindow.cpp
+++ b/src/kmainwindow.cpp
@@ -608,7 +608,12 @@ void KMainWindow::applyMainWindowSettings(const KConfigGroup &cg)
     d->letDirtySettings = false;
 
     if (!d->sizeApplied) {
+        winId(); // ensure there's a window created
         KWindowConfig::restoreWindowSize(windowHandle(), cg);
+        // NOTICE: QWindow::setGeometry() does NOT impact the backing QWidget geometry even if the platform
+        // window was created -> QTBUG-40584. We therefore copy the size here.
+        // TODO: remove once this was resolved in QWidget QPA
+        resize(windowHandle()->size());
         d->sizeApplied = true;
     }

that's it! fixes the bug, and no segfaults now!

(In reply to Hrvoje Senjan from comment #14)
> that's it! fixes the bug, and no segfaults now!

If you've already the Qt patch applied, simply creating the window handle (calling winId()) might be sufficient - evtl. accomplished by https://git.reviewboard.kde.org/r/119593/ ?

patch review: https://git.reviewboard.kde.org/r/120078/

Git commit 1b9eed7738470ddfd495ded2e023aef6b8d079e5 by Thomas Lübking.
Committed on 07/09/2014 at 10:56.
Pushed by luebking into branch 'master'.

fix kmainwindow size restorage, WA QTBUG 40584

This
a) ensures there's windowaHandle() to restore the size for
b) works around a pending Qt bug by explicitly coyping the
   restored QWindow size to the QWidget size
REVIEW: 120078

M  +6    -0    src/kmainwindow.cpp

http://commits.kde.org/kxmlgui/1b9eed7738470ddfd495ded2e023aef6b8d079e5