bind <key> refresh_inputline

This function causes the client to redraw the input line. It is mostly only useful when another process sends data to the client's tty, which sometimes corrupts the display of the input line (but not the actual contents).

This command is mostly deprecated, as REFRESH_SCREEN takes care of the input line, as well as the rest of the screen. It is only really useful for times when it may not be wise to refresh the rest of the screen, such as if there were special ANSI escape sequences in the display window or status bar. This is rarely the case, though.