[Various notes and disclaimers:

* Missing any code for "cvs rm" on a directory.

* Haven't tested this.  It does compile but I haven't run it.  Would
want a variety of sanity.sh test cases, of course.

* Need to think harder about how this interacts with -d and -P and so
on.  And about compatibility in general (maybe all the new
functionality is enabled by a configuration setting in CVSROOT/config?
That kind of issue).

* For now at least, I'm treating this as a separate issue from whether
"cvs add" on a directory is immediate or waits for a commit.  Might be
good to tackle the two at the same time, since they aren't completely
separate (and dealing with the compatibility questions all at once
might be easier).

* Probably want to think at least a bit about "_directory" versus
  "directory" as the name of the state.

-kingdon]

Index: ChangeLog
===================================================================
RCS file: /home2/cvsroot/ccvs/src/ChangeLog,v
retrieving revision 1.1672
diff -c -r1.1672 ChangeLog
*** ChangeLog	1998/12/19 04:52:40	1.1672
--- ChangeLog	1998/12/20 18:40:31
***************
*** 1,3 ****
--- 1,14 ----
+ 1998-12-20  Jim Kingdon
+ 
+ 	* rcs.c, cvs.h (RCS_checkin): New flag RCS_FLAGS_DIRECTORY, lets
+ 	us set the state to "directory".
+ 	* rcs.c, rcs.h (RCS_isdir): New function, to get whether state is
+ 	"directory".
+ 	* add.c (add_directory): Check in a directory revision when we add
+ 	a directory.
+ 	* update.c (update_dirent_proc): Don't create a new directory if
+ 	there is no directory revision.
+ 
  1998-12-16  Jim Meyering  <meyering@ascend.com>
  
  	* rcs.c (RCS_getdate): Handle the case in which a file is first
Index: add.c
===================================================================
RCS file: /home2/cvsroot/ccvs/src/add.c,v
retrieving revision 1.69
diff -c -r1.69 add.c
*** add.c	1998/09/01 13:54:40	1.69
--- add.c	1998/12/20 18:44:51
***************
*** 24,29 ****
--- 24,30 ----
   * file to be resurrected.
   */
  
+ #include <assert.h>
  #include "cvs.h"
  #include "savecwd.h"
  #include "fileattr.h"
***************
*** 700,705 ****
--- 701,738 ----
  #else
      Create_Admin (".", finfo->fullname, rcsdir, tag, date, nonbranch, 0);
  #endif
+ 
+     {
+ 	RCSNode *rcsnode;
+ 	int status;
+ 
+ 	/* Even if the directory existed, go ahead and check in a
+ 	   directory revision to the dir,v file, to patch it up in case
+ 	   the directory was created with an old version of CVS.  */
+ 	rcsnode = RCS_parse (finfo->file, finfo->repository);
+ 	if (rcsnode == NULL)
+ 	{
+ 	    error (0, 0, "cannot parse RCS file for %s", finfo->fullname);
+ 	    goto rcsdone;
+ 	}
+ 
+ 	/* FIXME: The case where tag != NULL is (I think) unhandled.  I
+            think we need to call RCS_getversion or some such to get a
+            numeric revision.  */
+ 	assert (tag == NULL);
+ 
+ 	status = RCS_checkin (rcsnode, NULL, message, tag,
+ 			      RCS_FLAGS_DIRECTORY);
+ 	if (status < 0)
+ 	    error (0, errno, "cannot checkin directory revision");
+ 	if (status <= 0)
+ 	    goto rcsdone;
+ 
+     rcsdone:
+ 	if (rcsnode != NULL)
+ 	    freercsnode (&rcsnode);
+     }
+ 
      if (tag)
  	free (tag);
      if (date)
Index: cvs.h
===================================================================
RCS file: /home2/cvsroot/ccvs/src/cvs.h,v
retrieving revision 1.194
diff -c -r1.194 cvs.h
*** cvs.h	1998/10/21 17:09:41	1.194
--- cvs.h	1998/12/20 18:02:25
***************
*** 415,420 ****
--- 415,421 ----
  #define RCS_FLAGS_QUIET 4
  #define RCS_FLAGS_MODTIME 8
  #define RCS_FLAGS_KEEPFILE 16
+ #define RCS_FLAGS_DIRECTORY 32
  
  extern int RCS_exec_rcsdiff PROTO ((RCSNode *rcsfile,
  				    char *opts, char *options,
Index: rcs.c
===================================================================
RCS file: /home2/cvsroot/ccvs/src/rcs.c,v
retrieving revision 1.209
diff -c -r1.209 rcs.c
*** rcs.c	1998/12/19 04:47:33	1.209
--- rcs.c	1998/12/20 18:03:03
***************
*** 3634,3639 ****
--- 3634,3660 ----
      return (version->dead);
  }
  
+ /* Return true if RCS revision with numeric revision TAG is a
+    directory revision.  */
+ int
+ RCS_isdir (rcs, rev)
+     RCSNode *rcs;
+     const char *rev;
+ {
+     Node *p;
+     RCSVers *version;
+ 
+     if (rcs->flags & PARTIAL)
+ 	RCS_reparsercsfile (rcs, (FILE **) NULL, (struct rcsbuffer *) NULL);
+ 
+     p = findnode (rcs->versions, rev);
+     if (p == NULL)
+ 	return (0);
+ 
+     version = (RCSVers *) p->data;
+     return (STREQ (version->state, "directory"));
+ }
+ 
  /* Return the RCS keyword expansion mode.  For example "b" for binary.
     Returns a pointer into storage which is allocated and freed along with
     the rest of the RCS information; the caller should not modify this
***************
*** 5068,5073 ****
--- 5089,5095 ----
  /* Check in to RCSFILE with revision REV (which must be greater than
     the largest revision) and message MESSAGE (which is checked for
     legality).  If FLAGS & RCS_FLAGS_DEAD, check in a dead revision.
+    If FLAGS & RCS_FLAGS_DIRECTORY, check in a directory revision.
     If FLAGS & RCS_FLAGS_QUIET, tell ci to be quiet.  If FLAGS &
     RCS_FLAGS_MODTIME, use the working file's modification time for the
     checkin time.  WORKFILE is the working file to check in from, or
***************
*** 5166,5171 ****
--- 5188,5195 ----
  	delta->state = xstrdup (RCSDEAD);
  	delta->dead = 1;
      }
+     else if (flags & RCS_FLAGS_DIRECTORY)
+ 	delta->state = xstrdup ("directory");
      else
  	delta->state = xstrdup ("Exp");
  
Index: rcs.h
===================================================================
RCS file: /home2/cvsroot/ccvs/src/rcs.h,v
retrieving revision 1.52
diff -c -r1.52 rcs.h
*** rcs.h	1998/08/26 17:22:30	1.52
--- rcs.h	1998/12/20 18:04:18
***************
*** 211,216 ****
--- 211,217 ----
  char *RCS_branch_head PROTO ((RCSNode *rcs, char *rev));
  
  int RCS_isdead PROTO((RCSNode *, const char *));
+ int RCS_isdir PROTO ((RCSNode *, const char *));
  char *RCS_getexpand PROTO ((RCSNode *));
  int RCS_checkout PROTO ((RCSNode *, char *, char *, char *, char *, char *,
  			 RCSCHECKOUTPROC, void *));
Index: update.c
===================================================================
RCS file: /home2/cvsroot/ccvs/src/update.c,v
retrieving revision 1.162
diff -c -r1.162 update.c
*** update.c	1998/11/12 20:24:45	1.162
--- update.c	1998/12/20 18:43:22
***************
*** 865,873 ****
--- 865,894 ----
  
      if (!isdir (dir))
      {
+ 	RCSNode *rcsnode;
+ 	char *rev;
+ 
  	/* if we aren't building dirs, blow it off */
  	if (!update_build_dirs)
  	    return (R_SKIP_ALL);
+ 
+ 	/* Now, if there is an RCS file for this directory, and it
+ 	   says that the relevant revision is not a directory
+ 	   revision, then skip it.  If there is no RCS file, the
+ 	   repository was written by an old version of CVS; so go
+ 	   ahead and create it like we always have.  */
+ 	rcsnode = RCS_parse (dir, repository);
+ 	if (rcsnode != NULL)
+ 	{
+ 	    int forget_it = 0;
+ 
+ 	    rev = RCS_getversion (rcsnode, tag, date, force_tag_match,
+ 				  (int *) NULL);
+ 	    forget_it = !RCS_isdir (rcsnode, rev);
+ 	    freercsnode (&rcsnode);
+ 	    if (forget_it)
+ 		return R_SKIP_ALL;
+ 	}
  
  	/* Various CVS administrators are in the habit of removing
  	   the repository directory for things they don't want any