ID 463244 - Dragging items out of a QTreeWidget causes Nuke to crash

Problem summary
Dragging items out of a QTreeWidget causes Nuke to crash.

This issue only seems to occur with dockable PySide Widgets, and not when the widget is displayed as a window.

Customer reported version
Nuke 12.2v2

Customer reported platform
windows10

Steps to reproduce

1) Open Nuke.

2) Run the following code in the Script Editor. This should create a new panel.

import nuke 
from nukescripts import panels
from PySide2.QtWidgets import QWidget, QVBoxLayout, QTreeWidget, QAbstractItemView, QTreeWidgetItem 

class TestTreeView(QWidget): 
    def __init__(self, parent=None): 
        super(TestTreeView, self).__init__(parent) 
        self.mainLayout = QVBoxLayout() 
        self.myTree = QTreeWidget() 
        self.myTree.setColumnCount(1) 
        self.myTree.setHeaderLabels(['num']) 
        self.mainLayout.addWidget(self.myTree) 
        self.myTree.setDragEnabled(True) 
        self.myTree.setDragDropMode(QAbstractItemView.InternalMove) 
        self.setLayout(self.mainLayout)

        items = [] 
        for i in range(10): 
            items.append(QTreeWidgetItem(str(i)))

            self.myTree.insertTopLevelItems(0, items)

        return None

pane = nuke.getPaneFor('Properties.1') 
panels.registerWidgetAsPanel('TestTreeView', 'Test Tree Panel', '3dexcite..NukeTestWindow', True).addToPane(pane)

3) Drag one of the items from the QTreeWidget into another panel (for example, the Node Graph). This will cause Nuke to instantly crash.

Expected behaviour
Nuke should not crash when dragging items out of a QTreeWidget.

Actual behaviour
Dragging items out of a QTreeWidget causes Nuke to crash.

Workaround
Unknown.

Reproduced by support

This bug has been reproduced in:
Nuke 12.2v4 - Windows 10 - Linux CentOS 7 - macOS 10.15 (Catalina)

Nuke 12.0v1 - Windows 10 - Linux CentOS 7 - macOS 10.15 (Catalina) - Regression

Unable to reproduce bug in:
Nuke 11.3v6 - Windows 10 - Linux CentOS 7 - macOS 10.13 (High Sierra)

Earliest version tested
Nuke 11.3v6
- This issue doesn't appear in this version and has regressed