SUMMARY
Krita crashes after copying a layer with a blending mode and using Paste into Active Layer.

STEPS TO REPRODUCE
1. Open a new document.
2. Draw something (so that the layer isn't empty).
3. Set the layer blending mode to something other than Normal (I used Multiply).
4. Copy the layer.
5. Use Paste into Active Layer.
6. Krita crashes.

SOFTWARE/OS VERSIONS
Occurs on 5.1.3 and 5.2.x git hash 8b427aea.

ADDITIONAL INFORMATION
Backtraces; for some reason the first one happens with the default crash logging and the second two when using lldb.
#1---
>Qt5Core.dll!QReadWriteLock::lockForRead+0x7  [C:/MingW-LLVM/include/c++/v1/atomic @ 981]
>libkritaimage.dll!KisTiledDataManager::KisTiledDataManager+0x74  [C:/kd/i/include/QtCore/qreadwritelock.h @ 106]
>   104:         if (q_val) {
>   105:             if ((q_val & quintptr(1u)) == quintptr(0u)) {
>>  106:                 readWriteLock()->lockForRead();
>   107:                 q_val |= quintptr(1u);
>   108:             }
>libkritaimage.dll!KisPaintDeviceData::prepareClone+0x55  [C:/kd/src/libs/image/kis_datamanager.h @ 46]
>    44:      */
>    45: KisDataManager(quint32 pixelSize, const quint8 *defPixel) : ACTUAL_DATAMGR(pixelSize, defPixel) {}
>>   46:     KisDataManager(const KisDataManager& dm) : ACTUAL_DATAMGR(dm) { }
>    47: 
>    48:     ~KisDataManager() override {
>libkritaimage.dll!KisPaintDevice::Private::cloneAllDataObjects+0x104  [C:/kd/src/libs/image/kis_paint_device.cc @ 170]
>   168:         if (!copyFrames) {
>   169:             if (m_data) {
>>  170:                 m_data->prepareClone(rhs->currentNonLodData(), true);
>   171:             } else {
>   172:                 m_data = toQShared(new KisPaintDeviceData(q, rhs->currentNonLodData(), true));
>libkritaimage.dll!KisPaintDevice::makeFullCopyFrom+0x97  [C:/kd/src/libs/image/kis_paint_device.cc @ 1114]
>  1112: 
>  1113:     // copy data objects with or without frames
>> 1114:     m_d->cloneAllDataObjects(rhs.m_d, copyMode == KritaUtils::CopyAllFrames);
>  1115: 
>  1116:     if (copyMode == KritaUtils::CopyAllFrames && rhs.m_d->framesInterface) {
>libkritaimage.dll!KisPaintDevice::KisPaintDevice+0x6d  [C:/kd/src/libs/image/kis_paint_device.cc @ 1104]
>  1102: {
>  1103:     if (this != &rhs) {
>> 1104:         makeFullCopyFrom(rhs, copyMode, newParentNode);
>  1105:     }
>  1106: }
>libkritaui.dll!KisPasteIntoActionFactory::run+0x106  [C:/kd/src/libs/ui/actions/KisPasteActionFactories.cpp @ 315]
>   313:     const KisPaintDevice *clipdev = KisClipboard::instance()->clipFromKritaLayers(image->bounds(),
>   314:                                                                             image->colorSpace()).data();
>>  315:     KisPaintDeviceSP clip = new KisPaintDevice(*clipdev);
>   316: 
>   317:     if (clip) {
>libkritaui.dll!KisSelectionManager::pasteInto+0x84  [C:/kd/src/libs/ui/kis_selection_manager.cc @ 371]
>   369: {
>   370:     KisPasteIntoActionFactory factory;
>>  371:     factory.run(m_view);
>   372: }
>   373: 
#2---
>  * frame #0: 0x00007fff0892137c libkritaimage.dll`KisPaintDevice::Private::currentNonLodData() const [inlined] QScopedPointer<KisRasterKeyframeChannel, QScopedPointerDeleter<KisRasterKeyframeChannel>>::isNull(this=0xfeeefeeefeeeff06) const at qscopedpointer.h:150:17
>    frame #1: 0x00007fff0892137c libkritaimage.dll`KisPaintDevice::Private::currentNonLodData() const [inlined] QScopedPointer<KisRasterKeyframeChannel, QScopedPointerDeleter<KisRasterKeyframeChannel>>::operator KisRasterKeyframeChannel* QScopedPointer<KisRasterKeyframeChannel, QScopedPointerDeleter<KisRasterKeyframeChannel>>::*(this=0xfeeefeeefeeeff06) const at qscopedpointer.h:134:16
>    frame #2: 0x00007fff0892137c libkritaimage.dll`KisPaintDevice::Private::currentNonLodData(this=0xfeeefeeefeeefeee) const at kis_paint_device.cc:497:13
>    frame #3: 0x00007fff08922f96 libkritaimage.dll`KisPaintDevice::Private::cloneAllDataObjects(this=0x000002236ae4ed60, rhs=0xfeeefeeefeeefeee, copyFrames=false) at kis_paint_device.cc:170:43
>    frame #4: 0x00007fff08919e37 libkritaimage.dll`KisPaintDevice::makeFullCopyFrom(this=0x0000022365352b80, rhs=0x000002230e8396d0, copyMode=CopySnapshot, newParentNode=0x0000000000000000) at kis_paint_device.cc:1114:10
>    frame #5: 0x00007fff08919d5d libkritaimage.dll`KisPaintDevice::KisPaintDevice(this=0x0000022365352b80, rhs=0x000002230e8396d0, copyMode=CopySnapshot, newParentNode=0x0000000000000000) at kis_paint_device.cc:1104:9
>    frame #6: 0x00007fff113c6656 libkritaui.dll`KisPasteIntoActionFactory::run(this=<unavailable>, viewManager=0x00000223411b15e0) at KisPasteActionFactories.cpp:315:33
>    frame #7: 0x00007fff111ae594 libkritaui.dll`KisSelectionManager::pasteInto(this=0x00000223411b2838) at kis_selection_manager.cc:371:13
#3---
>    * frame #0: 0x00007fff0891af52 libkritaimage.dll`KisPaintDevice::exactBounds() const [inlined] KisPaintDevice::Private::currentData(this=0x000001ff42ed3090) const at kis_paint_device.cc:528:28
>      frame #1: 0x00007fff0891af4e libkritaimage.dll`KisPaintDevice::exactBounds() const [inlined] KisPaintDevice::Private::cache(this=0x000001ff42ed3090) at kis_paint_device.cc:143:16
>      frame #2: 0x00007fff0891af4e libkritaimage.dll`KisPaintDevice::exactBounds(this=0x000001ff1eb0d770) const at kis_paint_device.cc:1295:17
>      frame #3: 0x00007fff113c666b libkritaui.dll`KisPasteIntoActionFactory::run(this=<unavailable>, viewManager=0x000001ff1dd9e1c0) at KisPasteActionFactories.cpp:318:34
>      frame #4: 0x00007fff111ae594 libkritaui.dll`KisSelectionManager::pasteInto(this=0x000001ff1dd9f418) at kis_selection_manager.cc:371:13