4:
Default settings.
Disable “Drag selection border to extend/shrink selection”.
Select a single-line string.
Drag and drop it.
Click at the beginning of the selection.
** The selection does not collapse. And see the Undo history.
Select a multi-line string.
Drag and drop it.
Click at the beginning of the selection.
** The selection did not collapse but changed upward. And see the Undo history.
Select a multi-line string.
Drag and drop it at the beginning of itself.
** The selection changed upward.