Update to Qt5.15 in MXE Octave release branch

A user of the Windows release of Octave 6.3 reported that they couldn’t start the GUI (bug #61017).
The GUI also didn’t start when using a nightly build from octave.space that was built using the release branch of MXE Octave. It started correctly for them with a nightly build that was built using the default branch of MXE Octave.
They tried replacing the Qt libraries in the released version with the Qt libraries from the version that worked for them. That made the GUI work for them in that “patched” version.

IIUC, that probably means that there is a bug in Qt 5.14 (used in the released version) that has since been fixed upstream.

Would it be ok to update Qt on the release branch of MXE Octave from version 5.14.2 to version 5.15.2 (which is the current version on the default branch)?

If that is ok, could we also repackage Octave 6.3 for Windows with the updated version of Qt?

What was the reason that we went back from 5.15.2 to 5.14.2 ? (I forgot the details, but TTBOMK there was a compelling motive.)
That said, in my crossbuilds (default Octave) I’m using Qt 5.15.2 and I see no issues - that is, none that are sufficiently nasty to make me enter bug reports :slight_smile:

Afaict, we didn’t go back from Qt 5.15.2 to 5.14.2. The release branch was never updated to the newer version. IIRC, that was because we couldn’t see a reason why we should do that update.
See also MXE-octave “default” and “release” branch.

Edit: There was bug #59426 about horizontal widget positions not being persistent with Qt5.15. That is fixed in Octave 6.3 IIUC.

We had a problem with widget positions not being restored properly when using Qt 5.15:

IIUC, Torsten committed a workaround for that issue.
That workaround is part of Octave 6.3 afaict.

I thought I was still seeing the problem with restoring the window layout even after all attempts to fix it. But if it was fixed at some point when building with Qt 5.15 and 5.15 also fixes the other reported problem, then it is fine with me to update and make a new build of Octave 6.3 for Windows.

Thanks you John for refreshing my memory of that old bug.

FWIW I still see minor issues with restoring windows layout in dev Octave (which uses Qt 5.15.2). It’s only that the vertical border between two docked panes stacked in a “column” sometimes moves upward to AFAICT some consistent position.
But I didn’t post a bug report because (1) it isn’t consistent behavior, and (2) AFAICT it only sometimes seems to happens if I “mix” Octave versions, that is, switch from a recent dev Octave build to an earlier one or even use 6.3.0, and (3) I simply didn’t investigate further - too busy with other things.

I suppose such minor issues don’t quite outweigh the bug where Octave wouldn’t start at all, do they. So I’d say upgrade the release branch to Qt 5.15.2.

The issue with not correctly restored widgets when using Qt 5.15 should definitely be fixed. I do not see any reason why not switch to Qt 5.15 in the MXE build.

@PhilipN: I can confirm the minor issues with vertical borders within “widget columns” but have not spend much time in it yet. I think this bug is far less annoying than the one with the wrong horizontal widget positions.

I don’t change docked pane layout very often, I only regularly undock and re-dock the VE pane & its subpanes. I haven’t met serious issues the last months with Qt 5.15.2 in dev Octave.
BTW what is the bug no. that this was all about? (widget positions not restored)

See above:

Thx Markus, I simply looked in the wrong place :frowning: A bug tracker search with various combinations of keywords gave quite a few hits, maybe I overlooked #59426 simply because it drowned in the results.

Is it okay to go ahead with this suggestion and resolve GNU Octave - Bugs: bug #61017, GUI doesn't work anymore, even... [Savannah] ?

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I hope my post wasn’t misleading. What I meant is that the issue with the wrong widget positions (bug #59426) has already been fixed, which was confirmed by @mmuetzel. My previous post might be read as if this bug still has to be fixed.

I’m currently cross-building with MXE Octave where I grafted the Qt updates to the release branch.


I can confirm the minor issues with vertical borders within “widget columns” but have not spend much time in it yet. I think this bug is far less annoying than the one with the wrong horizontal widget positions.

In case you didn’t notice (I think not that many people use the VE often): vertical borders also move upward between subpanes in the VE. A restart of Octave isn’t even needed, just docking and undocking the VE suffices to reproduce it.
Maybe this helps to find out where the bug is, as this would imply that saving/restoring GUI settings isn’t involved.

Qt5.15 compiled successfully on the release branch and the resulting bundle seems to be working correctly. So, I pushed those changes here:
mxe-octave: 8cfad4a44884
mxe-octave: 6821341b80cb

I’ll ask the original reporter in the motivating bug report if this fixes the error they are seeing.

Updating Qt seems to have fixed the crash on start for the original reporter in bug #61017.

IIRC, we decided to make minor releases every 3-4 months (unless there were no significant changes). Is this still the case? If so, the next minor release would be due in approx. 4-8 weeks from now. It would probably be ok to wait until then for an updated Windows installer. We could refer affected users to the nightly builds from octave.space until then.

I’d guess that we’ll probably release Octave 7.1.0 around the end of this year or the beginning of next year.
If we don’t want to make another minor release of Octave 6.x, it might be good to re-build the Windows installer for Octave 6.3.0 with the update. Any opinions?