Suggested new feature for rcsdiff

[Keith Thompson]

Currently, the rcsdiff command has a fixed list of options that it
passes on to diff.  According to the 5.7.94 documentation, this list is:

     -0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -B, -B, -C, -D, -F, -H, -I,
     -L, -U, -W, -a, -b, -c, -d, -e, -f, -h, -i, -n, -p, -t, -u, -w, -y,
     long options (that start with "--")

(I just noticed that "-B" is listed twice.)

The problem: The set of options supported by diff (GNU or otherwise)
is a moving target.  It can also collide with the set of options
supported by rcsdiff itself; for example, "diff -q" means "Report
only whether the files differ, not the details of the differences.",
but "rcsdiff -q" means "Commands work silently (unless there is an
error condition), and suppress warnings and prompts."

Suggestion: In addition to the existing hardwired diff options,
add a new option to specify a set of arguments to be passed through
to diff.

I'm not sure what the best syntax would be.  Ideally, it should be
easy to specify multiple arguments, but still possible to specify
a single argument that contains white space.

An option to specify which diff command to use might go well
with this.

-- 
Keith Thompson (The_Other_Keith) address@hidden  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"