When xterm is in cooked and UTF-8 mode, backspace visually correctly removes
one character, but in the background, only one byte is removed from the buffer,
which causes bugs: the propmt shown by the application can also be erased, and
the line that is finally accepted may not be the same as one sees.
For a more detailed report and some more information see this (as konsole
suffers from the same bug):
This is a duplicate of 1578.
Yes, you're right. Sorry for this duplicate... closing as appropriate...
*** This bug has been marked as a duplicate of 1578 ***