At Thu, 12 Oct 2000 02:25:09 +0900,
Hugh Sasse Staff Elec Eng <hgs / dmu.ac.uk> wrote:
> 
> brains hgs 33 %> ruby -v -e 'File.expand_path("finder.rb", nil)'
> ruby 1.6.1 (2000-09-27) [sparc-solaris2.5.1]
> -e:1:in `expand_path': failed to convert nil into String (TypeError)
>         from -e:1

1.4.6 doesn't work either.  i think the problem is implicit
expectation of string when arg = 2.

this patch works for me but not sure it's the right way.
--
            yashi

Index: file.c
===================================================================
RCS file: /home/cvsroot/ruby/file.c,v
retrieving revision 1.38
diff -u -u -r1.38 file.c
--- file.c      2000/10/10 07:03:17     1.38
+++ file.c      2000/10/11 20:44:28
@@ -1260,7 +1260,7 @@
     }
 #endif
     else if (!isdirsep(*s)) {
-       if (argc == 2) {
+       if (argc == 2 && !NIL_P(dname)) {
            dname = rb_file_s_expand_path(1, &dname);
            if (OBJ_TAINTED(dname)) tainted = 1;
            strcpy(buf, RSTRING(dname)->ptr);