- eval-last-history-line #!optional scriptprocedure
The function behind ,rl-!!.
This function is not added to the history unless script is true. DO NOT pass script as true, unless you know what you are doing: it makes it possible to accidentally cause an infinite loop if the previous command was also eval-last-history-line #t!!
The line does not have to be from the current session. Also, I don't know what happens when there isn't said line, but I reckon it'd cause a segfault; I'll see about fixing that in the 3.1 release.