QGraphicsTextItem crashes when you delete the complete text interactivly

To reproduce the issue do the following:

 Open QtCreator build with Qt 5.15.7 (other reversions may also work). Create a new Model diagram (New File : Modeling : Scratch Model), drag an "Item" on the diagram. Klick into name field (on the diagram, not the right panel). Move cursor to end of name. Press backspace to delete all characters -> QtCreator crashes when the last character is deleted.

Running with debugger clearly shows that this happens on handling the "backspace" key event in QGraphicsTextItem (.