Once directory's name in new directory dialog is entered, it can't be completely deleted.
Backspace and delete buttons deletes all entered text except one letter.
Select All -> Delete behaviour dot't work at all.
So, directory name consists of single letter can't be deleted

Reproducible: Always

Steps to Reproduce:
1. Open Krusader
2. Press F7 (New directory action)
3. Enter any text in "Directory's name field"
4. Try to delete entered text
Actual Results:  
One can delete all text except one letter.
Directory name consists of single letter can't be deleted 

Expected Results:  
All entered text can be deleted.
When directory's name field is empty, "OK" button becomes inactive

The bug is not dangerous, but wery annoying, when you need to work with directories a lot.