highlighting text in a widget tries to reorder the widget

The drag n' drop reordering captures all the mouse clicks, so when you try to highlight text in a text box, it tries to drag the widget instead,

Start by locating the widget drag-and-drop mouse handling and reproduce the problem by selecting text in a text box. Trace why clicks used for text selection initiate reordering; done means text can be highlighted without moving the widget, while intentional dragging still reorders it.

Written by the indexing model from the issue text.