🚀 go-pugleaf

GNU diff 1.4 exhibits the following behavior (under SunOS 4.0 on a Sun-3/60):

	% mkdir a b 
	% touch a/f b/f 
	% diff -rs a b 
	Files a/f and b/f are identical
	Files a and b are identical

The second message is wrong, because `a' and `b' are not regular files.
Here is a fix.

*** diff1.4/diff.c	Sat Nov  5 12:15:57 1988
--- diffnew/diff.c	Sat Nov  5 12:14:54 1988
***************
*** 537,543 ****
      close (inf[1].desc);
  
   done:
!   if (val == 0 && print_file_same_flag)
      message ("Files %s and %s are identical\n",
  	     inf[0].name, inf[1].name);
  
--- 537,543 ----
      close (inf[1].desc);
  
   done:
!   if (val == 0 && print_file_same_flag && !inf[0].dir_p)
      message ("Files %s and %s are identical\n",
  	     inf[0].name, inf[1].name);