Can't Save Shortcut Data

[MaxNarr]

Description

The data field of a shortcut (for example Whisper/shout -> Subchannel #1) will not be saved after restarting. After restarting the data field says "empty" instead of Subchannel #1. The rest of the shortcut is stored correctly.

The command line prompts this when pressing apply :QVariant::save: unable to save type 'ShortcutTarget' (type id: 65538).
The command line prompts this on startup:
./mumble <X>2024-12-11 22:31:02.804 Loading settings from "/home/coms/.config/Mumble/Mumble/mumble_settings.json" <W>2024-12-11 22:31:02.804 QVariant::load: unable to load type 65538. <W>2024-12-11 22:31:02.804 QVariant::load: unable to load type 65538.

Steps to reproduce

1. Open Settings Menu
2. Go to Shortcuts
3. Press add button
4. choose whisper/ shout in the "Function" section
5. in the "data" section choose a channel. For example "Subchannel Experimental Typo Fix #1"
6. restart mumble

Mumble version

1.6.0

Mumble component

Client

OS

Linux

Reproducible?

Yes

Additional information

Mumble was compiled using the latest available code from git on a raspbian on RPI 5.
Using this manual https://wikiarchiv.natenom.de/mumble/entwicklung/mumble-selbst-bauen.html

Relevant log output

No response

Screenshots

No response

[Krzmbrzl]

@davidebeatrici I strongly suspect this is due to some difference introduced with Qt 6 👀

[davidebeatrici]

The error is usually caused by the data type not being registered, but we're doing that:

mumble/src/mumble/Settings.h

Lines 71 to 87 in edd4588

	struct ShortcutTarget {
	bool bCurrentSelection = false;
	bool bUsers = true;
	QStringList qlUsers = {};
	QList< unsigned int > qlSessions = {};
	int iChannel = -3;
	QString qsGroup = {};
	bool bLinks = false;
	bool bChildren = false;
	bool bForceCenter = false;
	ShortcutTarget() = default;
	bool isServerSpecific() const;
	bool operator==(const ShortcutTarget &) const;
	};
	Q_DECLARE_METATYPE(ShortcutTarget)

mumble/src/mumble/Settings.cpp

Lines 513 to 521 in edd4588

	#if defined(Q_OS_WIN)
	GlobalShortcutWin::registerMetaTypes();
	#endif
	qRegisterMetaType< ShortcutTarget >("ShortcutTarget");
	qRegisterMetaType< ChannelTarget >("ChannelTarget");
	qRegisterMetaType< QVariant >("QVariant");
	qRegisterMetaType< PluginSetting >("PluginSetting");
	qRegisterMetaType< Search::SearchDialog::UserAction >("SearchDialog::UserAction");
	qRegisterMetaType< Search::SearchDialog::ChannelAction >("SearchDialog::ChannelAction");

One difference I'm aware of is the deprecation of qRegisterMetaTypeStreamOperators, in fact in #6516 all instances were surrounded by a Qt version check:

#if QT_VERSION < 0x060000
	qRegisterMetaTypeStreamOperators< ChannelTarget >("ChannelTarget");
	qRegisterMetaTypeStreamOperators< PluginSetting >("PluginSetting");
	qRegisterMetaTypeStreamOperators< ShortcutTarget >("ShortcutTarget");
#endif

From https://www.qt.io/blog/whats-new-in-qmetatype-qvariant:

With Qt 6, the first thing we did was to extend the information stored in QMetaType: Modern C++ is now almost 10 years old, so it was about time to store information about the move constructor in QMetaType. And to provide better support for overaligned types, we now also store the alignment requirements of your types. Moreover, we considered the registries to be a bit clunky. After all, why should we require you to call QMetaType::registerEqualsComparator() when we could already know this by simply looking at the type? So in Qt 6, QMetaType::registerEqualsComparator, QMetaType::registerComparators, qRegisterMetaTypeStreamOperators and QMetaType::registerDebugStreamOperator have been removed. The metatype system will instead know about those automatically.

I suspect we may have to implement the stream operators in the class ourselves.

And, if that's actually the case, I would expect the same issue with ChannelTarget and PluginSetting as well.