cd w/o cdpath

[Donn Cave <donn@u.washington.edu>]

I think that prim_cd() doesn't have the ability to cd to a directory within
the current directory, by default.  Only works if you make a cdpath with "."
in it.  My solution was to add "." as an implicit cdpath member, but perhaps
there would be better ways to do it.

(Something I found in the source: there are subscript ranges - so I think
 "shift" is now "* = $*(2 ... $#*)".  That's nice.  It would also be
 interesting to be able to assign to a list, so "x = $1; shift" would
 be "(x *) = $*", with the usual result of assigning one value to each
 identifier except the last, which would get all remaining values; any
 excess identifiers would get nil.)

	Donn Cave, University Computing Services, University of Washington
	donn@cac.washington.edu

-------------------------------
--- prim-etc.c	Wed Oct 14 13:10:33 1992
***************
*** 200,205 ****
--- 200,206 ----
  		return true;
  	}
  	if (list->next == NULL) {
+ 		register int cdpath_has_null = 0;
  		char *name = getstr(list->term);
  		if (isabsolute(name) || streq(name, ".") || streq(name, ".."))
  			if (chdir(name) == -1)
***************
*** 220,227 ****
  					testlen = pathlen;
  					test = erealloc(test, testlen);
  				}
! 				if (*dir == '\0')
  					strcpy(test, name);
  				else {
  					strcpy(test, dir);
  					if (!streq(test, "/"))		/* "//" is special to POSIX */
--- 221,230 ----
  					testlen = pathlen;
  					test = erealloc(test, testlen);
  				}
! 				if (*dir == '\0') {
! 					cdpath_has_null = 1;
  					strcpy(test, name);
+ 				}
  				else {
  					strcpy(test, dir);
  					if (!streq(test, "/"))		/* "//" is special to POSIX */
***************
*** 236,242 ****
  				}
  			}
  			RefEnd(path);
! 			fail("cd %s: directory not found", name);
  		}
  	}
  	fail("usage: cd [directory]");
--- 239,250 ----
  				}
  			}
  			RefEnd(path);
! 			if (cdpath_has_null || chdir(name) < 0) {
! 				fail("cd %s: directory not found", name);
! 			}
! 			else {
! 				return true;
! 			}
  		}
  	}
  	fail("usage: cd [directory]");