piggz@linux-f1uu ~/projects/build-gadget_crash-Desktop_Qt_5_8_0_GCC_64bit-Debug $ valgrind --leak-check=full ./gadget_crash 
==18569== Memcheck, a memory error detector
==18569== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==18569== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==18569== Command: ./gadget_crash
==18569== 
Created object
Created gadget
==18569== Invalid read of size 8
==18569==    at 0x57E18A9: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E2740: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E31EE: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E33D9: QV4::QMetaObjectWrapper::callConstructor(QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C11: QV4::QMetaObjectWrapper::constructInternal(QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C7B: QV4::QMetaObjectWrapper::construct(QV4::Managed const*, QV4::Scope&, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57FA44B: QV4::Runtime::method_constructActivationProperty(QV4::ExecutionEngine*, int, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x421509B: ???
==18569==    by 0x57B749B: QV4::Script::run() (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x56F3627: QJSEngine::evaluate(QString const&, QString const&, int) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x401BAC: main (main.cpp:34)
==18569==  Address 0xb4440d8 is 7 bytes after a block of size 1 alloc'd
==18569==    at 0x4C2C6FF: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18569==    by 0x4020C7: MyGadget::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (main.moc:146)
==18569==    by 0x5857B1B: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E2735: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E31EE: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E33D9: QV4::QMetaObjectWrapper::callConstructor(QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C11: QV4::QMetaObjectWrapper::constructInternal(QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C7B: QV4::QMetaObjectWrapper::construct(QV4::Managed const*, QV4::Scope&, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57FA44B: QV4::Runtime::method_constructActivationProperty(QV4::ExecutionEngine*, int, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x421509B: ???
==18569==    by 0x57B749B: QV4::Script::run() (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x56F3627: QJSEngine::evaluate(QString const&, QString const&, int) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569== 
==18569== Invalid read of size 1
==18569==    at 0x57E18AD: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E2740: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E31EE: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E33D9: QV4::QMetaObjectWrapper::callConstructor(QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C11: QV4::QMetaObjectWrapper::constructInternal(QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C7B: QV4::QMetaObjectWrapper::construct(QV4::Managed const*, QV4::Scope&, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57FA44B: QV4::Runtime::method_constructActivationProperty(QV4::ExecutionEngine*, int, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x421509B: ???
==18569==    by 0x57B749B: QV4::Script::run() (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x56F3627: QJSEngine::evaluate(QString const&, QString const&, int) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x401BAC: main (main.cpp:34)
==18569==  Address 0x20 is not stack'd, malloc'd or (recently) free'd
==18569== 
==18569== 
==18569== Process terminating with default action of signal 11 (SIGSEGV)
==18569==  Access not within mapped region at address 0x20
==18569==    at 0x57E18AD: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E2740: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E31EE: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E33D9: QV4::QMetaObjectWrapper::callConstructor(QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C11: QV4::QMetaObjectWrapper::constructInternal(QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C7B: QV4::QMetaObjectWrapper::construct(QV4::Managed const*, QV4::Scope&, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57FA44B: QV4::Runtime::method_constructActivationProperty(QV4::ExecutionEngine*, int, QV4::CallData*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x421509B: ???
==18569==    by 0x57B749B: QV4::Script::run() (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x56F3627: QJSEngine::evaluate(QString const&, QString const&, int) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x401BAC: main (main.cpp:34)
==18569==  If you believe this happened as a result of a stack
==18569==  overflow in your program's main thread (unlikely but
==18569==  possible), you can try to increase the size of the
==18569==  main thread stack using the --main-stacksize= flag.
==18569==  The main thread stack size used in this run was 8388608.
==18569== 
==18569== HEAP SUMMARY:
==18569==     in use at exit: 122,636 bytes in 1,063 blocks
==18569==   total heap usage: 2,121 allocs, 1,058 frees, 342,929 bytes allocated
==18569== 
==18569== 8 bytes in 1 blocks are definitely lost in loss record 23 of 992
==18569==    at 0x4C2CE1F: operator new[](unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18569==    by 0x5860257: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x585D483: QQmlPropertyCache::copyAndAppend(QMetaObject const*, int, QQmlPropertyRawData::Flags, QQmlPropertyRawData::Flags, QQmlPropertyRawData::Flags) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x56F463E: QJSEnginePrivate::createCache(QMetaObject const*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x5809F07: QQmlData::createPropertyCache(QJSEngine*, QObject*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57DEC1A: QV4::QObjectWrapper::create(QV4::ExecutionEngine*, QObject*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E148B: QV4::QObjectWrapper::wrap_slowPath(QV4::ExecutionEngine*, QObject*) (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E18D4: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E2740: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E31EE: ??? (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E33D9: QV4::QMetaObjectWrapper::callConstructor(QQmlPropertyData const&, QV4::ExecutionEngine*, QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569==    by 0x57E3C11: QV4::QMetaObjectWrapper::constructInternal(QV4::CallData*) const (in /data/piggz/sdks/Qt5.8.0/5.8/gcc_64/lib/libQt5Qml.so.5.8.0)
==18569== 
==18569== 80 bytes in 1 blocks are possibly lost in loss record 845 of 992
==18569==    at 0x4C2C08F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18569==    by 0xA759F16: ??? (in /usr/lib64/libGLdispatch.so.0.0.0)
==18569==    by 0xA75A14A: __glDispatchInit (in /usr/lib64/libGLdispatch.so.0.0.0)
==18569==    by 0xA4EC388: ??? (in /usr/lib64/libGLX.so.0.0.0)
==18569==    by 0x400F2D9: call_init.part.0 (in /lib64/ld-2.25.so)
==18569==    by 0x400F3E5: _dl_init (in /lib64/ld-2.25.so)
==18569==    by 0x4000E59: ??? (in /lib64/ld-2.25.so)
==18569== 
==18569== 80 bytes in 1 blocks are possibly lost in loss record 846 of 992
==18569==    at 0x4C2C08F: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==18569==    by 0xA759F16: ??? (in /usr/lib64/libGLdispatch.so.0.0.0)
==18569==    by 0xA75A31B: __glDispatchRegisterStubCallbacks (in /usr/lib64/libGLdispatch.so.0.0.0)
==18569==    by 0x66B98DA: ??? (in /usr/lib64/libGL.so.1.0.0)
==18569==    by 0x400F2D9: call_init.part.0 (in /lib64/ld-2.25.so)
==18569==    by 0x400F3E5: _dl_init (in /lib64/ld-2.25.so)
==18569==    by 0x4000E59: ??? (in /lib64/ld-2.25.so)
==18569== 
==18569== LEAK SUMMARY:
==18569==    definitely lost: 8 bytes in 1 blocks
==18569==    indirectly lost: 0 bytes in 0 blocks
==18569==      possibly lost: 160 bytes in 2 blocks
==18569==    still reachable: 122,468 bytes in 1,060 blocks
==18569==                       of which reachable via heuristic:
==18569==                         newarray           : 440 bytes in 1 blocks
==18569==         suppressed: 0 bytes in 0 blocks
==18569== Reachable blocks (those to which a pointer was found) are not shown.
==18569== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==18569== 
==18569== For counts of detected and suppressed errors, rerun with: -v
==18569== ERROR SUMMARY: 5 errors from 5 contexts (suppressed: 0 from 0)
Segmentation fault (core dumped)