Lmms hangs when loading a song with zynaddsubfx over an already opened song

[ycollet]

I use lmms from git repo on fedora 21 64 bits.
I opened https://lmms.io/lsp/?action=show&file=4274 (a song with a zynaddsubfx song).
I played it and then, I play this song: https://lmms.io/lsp/?action=show&file=819
lmms hangs while loading.
Here is the gdb trace:
(gdb) where

#0  0x0000000000000000 in  ()
#1  0x00007ffff693b993 in QObject::~QObject() () at /lib64/libQtCore.so.4
#2  0x00007fffca272b29 in NulEngine::~NulEngine() (this=0xba3bf50, __in_chrg=<optimized out>, __vtt_parm=<optimized out>)
    at /home/collette/repositories/lmms/plugins/zynaddsubfx/zynaddsubfx/src/Nio/NulEngine.cpp:76
#3  0x00007fffca224737 in LocalZynAddSubFx::~LocalZynAddSubFx() (this=0xba3bd80, __in_chrg=<optimized out>)
    at /home/collette/repositories/lmms/plugins/zynaddsubfx/LocalZynAddSubFx.cpp:92
#4  0x00007fffc9fec93a in ZynAddSubFxInstrument::~ZynAddSubFxInstrument() (this=0x7fffea735f60, __in_chrg=<optimized out>)
    at /home/collette/repositories/lmms/plugins/zynaddsubfx/ZynAddSubFx.cpp:150
#5  0x00007fffc9fecae9 in ZynAddSubFxInstrument::~ZynAddSubFxInstrument() (this=0x7fffea735f60, __in_chrg=<optimized out>)
    at /home/collette/repositories/lmms/plugins/zynaddsubfx/ZynAddSubFx.cpp:155
#6  0x000000000058400d in InstrumentTrack::~InstrumentTrack() (this=0x7fffea733b20, __in_chrg=<optimized out>)
    at /home/collette/repositories/lmms/src/tracks/InstrumentTrack.cpp:161
#7  0x00000000005841a9 in InstrumentTrack::~InstrumentTrack() (this=0x7fffea733b20, __in_chrg=<optimized out>)
    at /home/collette/repositories/lmms/src/tracks/InstrumentTrack.cpp:162
#8  0x000000000053cf42 in TrackContainerView::clearAllTracks() (this=0xeefee0) at /home/collette/repositories/lmms/src/gui/TrackContainerView.cpp:333
#9  0x00000000004eb07c in Song::clearProject() (this=this@entry=0xa9c5b0) at /home/collette/repositories/lmms/src/core/Song.cpp:771
#10 0x00000000004ec38b in Song::loadProject(QString const&) (this=0xa9c5b0, fileName=...) at /home/collette/repositories/lmms/src/core/Song.cpp:934
#11 0x000000000052a7c5 in MainWindow::openRecentlyOpenedProject(QAction*) (this=0xc62420, _action=<optimized out>)
    at /home/collette/repositories/lmms/src/gui/MainWindow.cpp:829
#12 0x00007ffff6936cdc in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () at /lib64/libQtCore.so.4
#13 0x00007ffff74e6ed2 in QMenu::triggered(QAction*) () at /lib64/libQtGui.so.4
#14 0x00007ffff74e8430 in QMenuPrivate::_q_actionTriggered() () at /lib64/libQtGui.so.4
#15 0x00007ffff6936cdc in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () at /lib64/libQtCore.so.4
#16 0x00007ffff7092792 in QAction::triggered(bool) () at /lib64/libQtGui.so.4
#17 0x00007ffff7094317 in QAction::activate(QAction::ActionEvent) () at /lib64/libQtGui.so.4
#18 0x00007ffff74e71dd in QMenuPrivate::activateCausedStack(QList<QPointer<QWidget> > const&, QAction*, QAction::ActionEvent, bool) () at /lib64/libQtGui.so.4
#19 0x00007ffff74ebb99 in QMenuPrivate::activateAction(QAction*, QAction::ActionEvent, bool) () at /lib64/libQtGui.so.4
#20 0x00007ffff70ec118 in QWidget::event(QEvent*) () at /lib64/libQtGui.so.4
#21 0x00007ffff74efb7b in QMenu::event(QEvent*) () at /lib64/libQtGui.so.4
#22 0x00007ffff7098efc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#23 0x00007ffff709fabf in QApplication::notify(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#24 0x00007ffff692216d in QCoreApplication::notifyInternal(QObject*, QEvent*) () at /lib64/libQtCore.so.4
#25 0x00007ffff709f11f in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) ()
    at /lib64/libQtGui.so.4
#26 0x00007ffff71158fa in QETWidget::translateMouseEvent(_XEvent const*) () at /lib64/libQtGui.so.4
#27 0x00007ffff7113f5c in QApplication::x11ProcessEvent(_XEvent*) () at /lib64/libQtGui.so.4
#28 0x00007ffff713bff4 in x11EventSourceDispatch(_GSource*, int (*)(void*), void*) () at /lib64/libQtGui.so.4
#29 0x00007ffff3e3f7fb in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
#30 0x00007ffff3e3fb98 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
#31 0x00007ffff3e3fc4c in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#32 0x00007ffff695149e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#33 0x00007ffff713c176 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtGui.so.4
#34 0x00007ffff6920cc1 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
---Type <return> to continue, or q <return> to quit---
#35 0x00007ffff6921025 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#36 0x00007ffff6926709 in QCoreApplication::exec() () at /lib64/libQtCore.so.4
#37 0x0000000000485670 in main(int, char**) (argc=1, argv=0x7fffffffdd48) at /home/collette/repositories/lmms/src/core/main.cpp:542

A "temporary" workaround:

diff --git a/plugins/zynaddsubfx/LocalZynAddSubFx.cpp b/plugins/zynaddsubfx/LocalZynAddSubFx.cpp
index 7bb7e76..33ced6d 100644
--- a/plugins/zynaddsubfx/LocalZynAddSubFx.cpp
+++ b/plugins/zynaddsubfx/LocalZynAddSubFx.cpp
@@ -89,7 +89,7 @@ LocalZynAddSubFx::LocalZynAddSubFx() :
 LocalZynAddSubFx::~LocalZynAddSubFx()
 {
        delete m_master;
-       delete m_ioEngine;
+       //if (m_ioEngine) delete m_ioEngine;

        if( --s_instanceCount == 0 )
        {

[tresf]

Thanks for the bug report.

Reminder, using ``` around stack traces will prevent #auto-linking a bunch of old bug reports, edited. :)

[ycollet]

OK, thanks for the comment and the edit.

[zonkmachine]

This would have been fixed in #2118
Closing. Please reopen if you see this on current master!