🚀 go-pugleaf

If you have something typed on the line and hit ^R, you get the
reverse i-search prompt with the current contents, which would lead you
to believe that the search had found the previous line with what you
have typed so far.  but no, the search won't start until you type
another character, and what you have typed so far is ignored.

The behaviour where something on the line followed by ^R actually
searches back immediately is similar to that of tcsh; the one where
the prompt would be cleared would be ok, but I suspect that most often,
if you have something typed when you hit ^R it is because you had
that command in mind and you've just realized that you had issued
a similar one before..., so clearing the prompt would usually mean
more typing.