Steps to reproduce the problem:
1. Create an input
2. Create a div with some text
3. Register handler for drop and dropover events
4. Type in some text inside the input
5. Select any part of the text from the div
6. Drop the selected part to the input, don't release a mouse and move it over the text in the input
7. The browser displays you the cursor position inside the input at which the selected text will be placed at the end of the drop action
8. Observe selectionStart and selectionEnd properties of the input elements on drop and dropover events.

Mark WontFix since Chrome works as expected.

Drag-and-drop caret and selection caret are different entity. DnD-Caret doesn't move selection in text field.

So, then how to get DnD caret position just before the drop? Right now, it's only possible to get the selection after the native drop is completed, so taht, if we want restring the input with only letters and digits we cannot do it before the drop, only after it complets we could get the resulted value and remove the selection if it does not match the criteria. As I said initially this is not a big deal but it will be a nice future if it's possible to restrict the input before than making corrections after.