'git checkout -p' is a bit confusing...

I noticed this a little while back, but thought it may have been my
own misunderstanding.  I wanted to selectively revert part of a file,
so I used 'git checkout -p filename'.  Then I needed to edit the hunk,
and got something like this:

    # Manual hunk edit mode -- see bottom for a quick guide
    @@ -236,6 +236,12 @@ int run_add_interactive(const char *revision,
const char *patch_mode,
            }
            args[ac] = NULL;

    +        for (i=0; i < ac; i++)
    +          {
    +            fprintf(stderr, "%s ", args[i]);
    +          }
    +        fprintf(stderr, "\n");
    +
    # ---
    # To remove '+' lines, make them ' ' lines (context).
    # To remove '-' lines, delete them.
    # Lines starting with # will be removed.
    #
    # If the patch applies cleanly, the edited hunk will immediately be
    # marked for discarding. If it does not apply cleanly, you will be given
    # an opportunity to edit again. If all lines of the hunk are removed,
    # then the edit is aborted and the hunk is left unchanged.

Since the diff was showing me the forward direction (from the base to
modified working tree), I expected that when I left the +'s in there,
that it was going to leave my hunk.  Unfortunately, it discarded my
hunk.  I can see the text at the bottom, and now it makes sense, but I
wonder if there's a way to make it so that you can edit the patch to
look the way you want, and keep those bits (in much the same way as
'git add -p' works)?

I hope that makes sense. :-)

Thank you!

-John