fix: 0 interpreted as command unless currently inputting a number
What this merge request does:
Currently, there is (believed to be) a bug where when the user inputs '0' it is treated as a number instead of as the '0' command, which sets the cursor to the beginning of the current line.
This PR fixes that by simply checking if n is unset, if it is then 0 is a command, if not then 0 is added to n.