How to reset line at cursor if no forward search results are found?

Question

In my .bash_profile, I've bound the up/down arrow keys to the history-search functions:

if [[ $- == *i* ]]
then
    bind '"\e[A": history-search-backward'
    bind '"\e[B": history-search-forward'
fi

This allows me to search my history backwards using the up arrow and forwards using the down one. However, if I'm searching forwards and I get to the last command, I want to be able to press down again to remove the search result at the cursor. For example, if | is the cursor:

$ echo  hello| 
hello
$ echo  |

Pressing the up arrow key here will do:

$ echo  hello|
hello
$ echo |hello

I would like to be able to press the down arrow key to remove the hello (i.e the search result) so that I'm back at:

$ echo  hello| 
hello
$ echo  |

Apologies if this has been asked before, I couldn't find an answer myself.