Having a QQmlImageProviderBase-derived class providing some images to QQuickView causes the process to crash when closing the QQuickView window...

The issue is easily reproducible through the attached sample project (sample.tar.gz)... Simply launch the application and close the window... in application output you should see something like:

glibc detected * free(): invalid pointer: 0×091ec694 *
=== Backtrace: =====
/lib/i386-linux-gnu/libc.so.6(0×75ee2)[0xb5c1fee2]
/usr/lib/i386-linux-gnu/libstdc+.so.6(ZdlPv+0×1f)[0xb5e1b51f]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN21QQmlImageProviderBaseD0Ev+0×24)[0xb7136110]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(+0×211f59)[0xb713cf59]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(+0×2138b3)[0xb713e8b3]
/opt/Qt/5.3/gcc/lib/libQt5Core.so.5(_ZN9QHashData11free_helperEPFvPNS_4NodeEE+0×4a)[0xb5f40e7a]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN17QQmlEnginePrivateD1Ev+0×8ab)[0xb71378c5]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN17QQmlEnginePrivateD0Ev+0×1c)[0xb7137a7c]
/opt/Qt/5.3/gcc/lib/libQt5Core.so.5(_ZN7QObjectD1Ev+0×6a1)[0xb6173031]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN9QJSEngineD1Ev+0×36)[0xb70352b6]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN10QQmlEngineD1Ev+0xf0)[0xb71398fe]
/opt/Qt/5.3/gcc/lib/libQt5Qml.so.5(_ZN10QQmlEngineD0Ev+0×1c)[0xb71399e2]
/opt/Qt/5.3/gcc/lib/libQt5Core.so.5(_ZN14QObjectPrivate14deleteChildrenEv+0×6c)[0xb616e4ac]
/opt/Qt/5.3/gcc/lib/libQt5Core.so.5(_ZN7QObjectD1Ev+0×661)[0xb6172ff1]
/opt/Qt/5.3/gcc/lib/libQt5Gui.so.5(_ZN7QWindowD2Ev+0×6d)[0xb646a7bd]
/opt/Qt/5.3/gcc/lib/libQt5Quick.so.5(_ZN12QQuickWindowD1Ev+0xd9)[0xb74878e9]
/opt/Qt/5.3/gcc/lib/libQt5Quick.so.5(_ZN10QQuickViewD1Ev+0×9a)[0xb753925a]
[...]

ATTENTION: the same exact application works fine with Qt 5.2.1 on all platforms I have tested.