crash when ctrl clicking hotcue number three times on macOS

[foss-]

macOS 12.5.1 (Intel mac)
2.4-alpha-1282-gc9d95818b6 (main)

Reproduce

• Load track with hotcues or create a hotcue
• ctrl+click on hotcue three times

Currently
On first click Hotcue details open
On second click Hotcue details close
On third click Mixxx crashes
Crash (1 year): https://bin.disroot.org/?bfa39408ab0c180f#B9JDTUQyp1ZFp642sXJnnyU5zEJRe2U2LyaHrLEge8Zj

Expected
No crash

@daschuer mentioned the trace looks familiar to #9687 (fixed in 2.3.0)

Wondering if this is yet another variety of #10839 behavior?

[ronso0]

This is not a crash but a hit debug assert:

mixxx/src/mixxxapplication.cpp

Lines 111 to 126 in c9d9581

	bool MixxxApplication::notify(QObject* target, QEvent* event) {
	// All touch events are translated into two simultaneous events: one for
	// the target QWidgetWindow and one for the target QWidget.
	// A second touch becomes a mouse move without additional press and release
	// events.
	switch (event->type()) {
	case QEvent::MouseButtonPress: {
	QMouseEventEditable* mouseEvent = static_cast<QMouseEventEditable*>(event);
	if (mouseEvent->source() == Qt::MouseEventSynthesizedByQt &&
	mouseEvent->button() == Qt::LeftButton &&
	touchIsRightButton()) {
	// Assert the assumption that QT synthesizes only one click at a time
	// = two events (see above)
	VERIFY_OR_DEBUG_ASSERT(m_rightPressedButtons < 2) {
	break;
	}

As noticed in #10839 the reason is very likely the same: no button release is emitted when using Ctrl + left-click on macOS.
I guess no one would close a popup with another right-click, besides debug assertions are not fatal in releases.
Thus: low prio : )

[foss-]

no longer reproducible testing build from #10839

[ronso0]

Huuh? #10839 only touches the knob/slider event handlers.
Is DEBUG_ASSERTIONS_FATAL turned off for some strange reason?

[foss-]

Unsure how to tell. But I am no longer able to trigger the crash debug assert which I previously was able to reliable reproduce.

[ronso0]

You didn't Ctrl+click anything else in Mixxx after launch, only 3 x on the hotcue button?

[foss-]

RIght and the hotcue details open and close in alternating order.

[foss-]

2.3.3 Qt: 5.12.3
2.4.0 Qt: 5.12.4
So maybe that is the difference and issue is limited to 5.12.4 😵‍💫

[ronso0]

...that, or there are some more debug assertions in 2.4 (didn't look at the backtrace, yet)

[ronso0]

Wait, this is about the hotcue button, not about hotcue markers on waveforms, right?

[foss-]

Wait, this is about the hotcue button, not about hotcue markers on waveforms, right?

ack

[ronso0]

Is fixed after #10869 was merged to 2.3.4?

[foss-]

macOS 12.6
Mixxx 2.3.3-50-g5e551aaaa1 (HEAD) from https://github.com/mixxxdj/mixxx/actions/runs/3103325423#artifacts

No longer crashes. Closing.
Probably not the only oddity fixed by the change.