--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2009-09-16  Eric Blake  <ebb9@byu.net>
+
+	rmdir: work around cygwin 1.5.x and mingw bugs
+	* m4/rmdir.m4 (gl_FUNC_RMDIR): Detect the bugs.
+	* lib/rmdir.c (rmdir): Work around it.
+	* modules/rmdir (Status, Notice): No longer obsolete.
+	(Files): Add dos.m4.
+	(Depends-on): Add unistd.
+	(configure.ac): Set witnesses.
+	(License): Relax to LGPLv2+.
+	* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Set defaults.
+	* modules/unistd (Makefile.am): Substitute witnesses.
+	* lib/unistd.in.h (rmdir): Declare replacement.
+	* doc/posix-functions/rmdir.texi (rmdir): Document this.
+	* modules/rmdir-tests: New tests.
+	* tests/test-rmdir.c: Likewise.
+
 2009-09-15  Eric Blake  <ebb9@byu.net>
 
 	fchdir: improve use of replacement functions

--- a/doc/posix-functions/rmdir.texi
+++ b/doc/posix-functions/rmdir.texi
@@ -9,6 +9,14 @@
 Portability problems fixed by Gnulib:
 @itemize
 @item
+This function mistakenly removes a directory with
+@code{rmdir("dir/./")} on some platforms:
+Cygwin 1.5.x.
+@item
+This function fails with @code{EINVAL} instead of the expected
+@code{ENOTDIR} for @code{rmdir("file/")} on some platforms:
+mingw.
+@item
 This function is missing on some old platforms.
 @end itemize
 
@@ -17,4 +25,9 @@
 @item
 When @code{rmdir} fails because the specified directory is not empty, the
 @code{errno} value is system dependent.
+@item
+POSIX requires that @code{rmdir("link-to-empty/")} remove @file{empty}
+and leave @file{link-to-empty} as a dangling symlink.  This is
+counter-intuitive, so some systems fail with @code{ENOTDIR} instead:
+glibc
 @end itemize

--- a/lib/rmdir.c
+++ b/lib/rmdir.c
@@ -1,6 +1,6 @@
-/* BSD compatible remove directory function for System V
+/* Work around rmdir bugs.
 
-   Copyright (C) 1988, 1990, 1999, 2003, 2004, 2005, 2006 Free
+   Copyright (C) 1988, 1990, 1999, 2003, 2004, 2005, 2006, 2009 Free
    Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
@@ -18,18 +18,43 @@
 
 #include <config.h>
 
-#include <sys/types.h>
-#include <sys/stat.h>
+#include <unistd.h>
+
 #include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
-/* rmdir adapted from GNU tar.  */
+#undef rmdir
 
 /* Remove directory DIR.
    Return 0 if successful, -1 if not.  */
 
 int
-rmdir (char const *dir)
+rpl_rmdir (char const *dir)
 {
+#if HAVE_RMDIR
+  /* Work around cygwin 1.5.x bug where rmdir("dir/./") succeeds.  */
+  size_t len = strlen (dir);
+  int result;
+  while (len && ISSLASH (dir[len - 1]))
+    len--;
+  if (len && dir[len - 1] == '.' && (1 == len || ISSLASH (dir[len - 2])))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  result = rmdir (dir);
+  /* Work around mingw bug, where rmdir("file/") fails with EINVAL
+     instead of ENOTDIR.  We've already filtered out trailing ., the
+     only reason allowed by POSIX for EINVAL.  */
+  if (result == -1 && errno == EINVAL)
+    errno = ENOTDIR;
+  return result;
+
+#else /* !HAVE_RMDIR */
+  /* rmdir adapted from GNU tar.  FIXME: Delete this implementation in
+     2010 if no one reports a system with missing rmdir.  */
   pid_t cpid;
   int status;
   struct stat statbuf;
@@ -70,4 +95,5 @@
 	}
       return 0;
     }
+#endif /* !HAVE_RMDIR */
 }

--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -672,6 +672,21 @@
 #endif
 
 
+#if @GNULIB_RMDIR@
+# if @REPLACE_RMDIR@
+#  define rmdir rpl_rmdir
+/* Remove the directory DIR.  */
+extern int rmdir (char const *name);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef rmdir
+# define rmdir(n) \
+    (GL_LINK_WARNING ("rmdir is unportable - " \
+                      "use gnulib module rmdir for portability"), \
+     rmdir (n))
+#endif
+
+
 #if @GNULIB_SLEEP@
 /* Pause the execution of the current thread for N seconds.
    Returns the number of seconds left to sleep.

--- a/m4/rmdir.m4
+++ b/m4/rmdir.m4
@@ -1,4 +1,4 @@
-# rmdir.m4 serial 4
+# rmdir.m4 serial 5
 dnl Copyright (C) 2002, 2005, 2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,5 +6,37 @@
 
 AC_DEFUN([gl_FUNC_RMDIR],
 [
+  AC_REQUIRE([gl_AC_DOS])
+  dnl FIXME: simplify this module in 2010 if no one reports a missing rmdir
   AC_REPLACE_FUNCS([rmdir])
+  if test $ac_cv_func_rmdir = no; then
+    REPLACE_RMDIR=1
+    # If someone lacks rmdir, make configure fail, and request
+    # a bug report to inform us about it.
+    if test x"$SKIP_RMDIR_CHECK" != xyes; then
+      AC_MSG_FAILURE([Your system lacks the rmdir function.
+	      Please report this, along with the output of "uname -a", to the
+	      bug-coreutils@gnu.org mailing list.  To continue past this point,
+	      rerun configure with SKIP_RMDIR_CHECK=yes.
+	      E.g., ./configure SKIP_RMDIR_CHECK=yes])
+    fi
+  else
+    dnl Detect cygwin 1.5.x bug.
+    AC_CACHE_CHECK([whether rmdir works], [gl_cv_func_rmdir_works],
+      [mkdir conftest.dir
+       touch conftest.file
+       AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+           [[#include <stdio.h>
+             #include <errno.h>
+]], [[return !rmdir ("conftest.file/") || errno != ENOTDIR
+       || !rmdir ("conftest.dir/./");]])],
+         [gl_cv_func_rmdir_works=yes], [gl_cv_func_rmdir_works=no],
+         [gl_cv_func_rmdir_works="guessing no"])
+       rm -rf conftest.dir conftest.file])
+    if test x"$gl_cv_func_rmdir_works" != xyes; then
+      REPLACE_RMDIR=1
+      AC_LIBOBJ([rmdir])
+    fi
+  fi
 ])

--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,4 +1,4 @@
-# unistd_h.m4 serial 26
+# unistd_h.m4 serial 27
 dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -56,6 +56,7 @@
   GNULIB_PIPE2=0;            AC_SUBST([GNULIB_PIPE2])
   GNULIB_READLINK=0;         AC_SUBST([GNULIB_READLINK])
   GNULIB_READLINKAT=0;       AC_SUBST([GNULIB_READLINKAT])
+  GNULIB_RMDIR=0;            AC_SUBST([GNULIB_RMDIR])
   GNULIB_SLEEP=0;            AC_SUBST([GNULIB_SLEEP])
   GNULIB_SYMLINKAT=0;        AC_SUBST([GNULIB_SYMLINKAT])
   GNULIB_UNISTD_H_GETOPT=0;  AC_SUBST([GNULIB_UNISTD_H_GETOPT])
@@ -97,6 +98,7 @@
   REPLACE_LCHOWN=0;       AC_SUBST([REPLACE_LCHOWN])
   REPLACE_LINK=0;         AC_SUBST([REPLACE_LINK])
   REPLACE_LSEEK=0;        AC_SUBST([REPLACE_LSEEK])
+  REPLACE_RMDIR=0;        AC_SUBST([REPLACE_RMDIR])
   REPLACE_WRITE=0;        AC_SUBST([REPLACE_WRITE])
   UNISTD_H_HAVE_WINSOCK2_H=0; AC_SUBST([UNISTD_H_HAVE_WINSOCK2_H])
   UNISTD_H_HAVE_WINSOCK2_H_AND_USE_SOCKETS=0;

--- a/modules/rmdir
+++ b/modules/rmdir
@@ -1,21 +1,18 @@
 Description:
 rmdir() function: delete a directory.
 
-Status:
-obsolete
-
-Notice:
-This module is obsolete.
-
 Files:
 lib/rmdir.c
+m4/dos.m4
 m4/rmdir.m4
 
 Depends-on:
 sys_stat
+unistd
 
 configure.ac:
 gl_FUNC_RMDIR
+gl_UNISTD_MODULE_INDICATOR([rmdir])
 
 Makefile.am:
 
@@ -23,7 +20,7 @@
 <unistd.h>
 
 License:
-GPL
+LGPLv2+
 
 Maintainer:
-Jim Meyering
+Jim Meyering, Eric Blake

new file mode 100644
--- /dev/null
+++ b/modules/rmdir-tests
@@ -0,0 +1,11 @@
+Files:
+tests/test-rmdir.c
+
+Depends-on:
+
+configure.ac:
+AC_CHECK_FUNCS_ONCE([symlink])
+
+Makefile.am:
+TESTS += test-rmdir
+check_PROGRAMS += test-rmdir

--- a/modules/unistd
+++ b/modules/unistd
@@ -49,6 +49,7 @@
 	      -e 's|@''GNULIB_PIPE2''@|$(GNULIB_PIPE2)|g' \
 	      -e 's|@''GNULIB_READLINK''@|$(GNULIB_READLINK)|g' \
 	      -e 's|@''GNULIB_READLINKAT''@|$(GNULIB_READLINKAT)|g' \
+	      -e 's|@''GNULIB_RMDIR''@|$(GNULIB_RMDIR)|g' \
 	      -e 's|@''GNULIB_SLEEP''@|$(GNULIB_SLEEP)|g' \
 	      -e 's|@''GNULIB_SYMLINKAT''@|$(GNULIB_SYMLINKAT)|g' \
 	      -e 's|@''GNULIB_UNISTD_H_GETOPT''@|$(GNULIB_UNISTD_H_GETOPT)|g' \
@@ -89,6 +90,7 @@
 	      -e 's|@''REPLACE_LCHOWN''@|$(REPLACE_LCHOWN)|g' \
 	      -e 's|@''REPLACE_LINK''@|$(REPLACE_LINK)|g' \
 	      -e 's|@''REPLACE_LSEEK''@|$(REPLACE_LSEEK)|g' \
+	      -e 's|@''REPLACE_RMDIR''@|$(REPLACE_RMDIR)|g' \
 	      -e 's|@''REPLACE_WRITE''@|$(REPLACE_WRITE)|g' \
 	      -e 's|@''UNISTD_H_HAVE_WINSOCK2_H''@|$(UNISTD_H_HAVE_WINSOCK2_H)|g' \
 	      -e 's|@''UNISTD_H_HAVE_WINSOCK2_H_AND_USE_SOCKETS''@|$(UNISTD_H_HAVE_WINSOCK2_H_AND_USE_SOCKETS)|g' \

new file mode 100644
--- /dev/null
+++ b/tests/test-rmdir.c
@@ -0,0 +1,125 @@
+/* Tests of rmdir.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009.  */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#if !HAVE_SYMLINK
+# define symlink(a,b) (-1)
+#endif
+
+#define ASSERT(expr) \
+  do                                                                         \
+    {                                                                        \
+      if (!(expr))                                                           \
+	{                                                                    \
+	  fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__);  \
+	  fflush (stderr);                                                   \
+	  abort ();                                                          \
+	}                                                                    \
+    }                                                                        \
+  while (0)
+
+#define BASE "test-rmdir.t"
+
+int
+main ()
+{
+  /* Remove any leftovers from a previous partial run.  */
+  ASSERT (system ("rm -rf " BASE "*") == 0);
+
+  /* Setup.  */
+  ASSERT (mkdir (BASE "dir", 0700) == 0);
+  ASSERT (close (creat (BASE "dir/file", 0600)) == 0);
+
+  /* Basic error conditions.  */
+  errno = 0;
+  ASSERT (rmdir ("") == -1);
+  ASSERT (errno == ENOENT);
+  errno = 0;
+  ASSERT (rmdir (BASE "nosuch") == -1);
+  ASSERT (errno == ENOENT);
+  errno = 0;
+  ASSERT (rmdir (BASE "nosuch/") == -1);
+  ASSERT (errno == ENOENT);
+  errno = 0;
+  ASSERT (rmdir (".") == -1);
+  ASSERT (errno == EINVAL || errno == EBUSY);
+  /* Resulting errno after ".." or "/" is too varied to test; it is
+     reasonable to see any of EINVAL, EBUSY, EEXIST, ENOTEMPTY,
+     EACCES, EPERM.  */
+  ASSERT (rmdir ("..") == -1);
+  ASSERT (rmdir ("/") == -1);
+  ASSERT (rmdir ("///") == -1);
+  errno = 0;
+  ASSERT (rmdir (BASE "dir/file/") == -1);
+  ASSERT (errno == ENOTDIR);
+
+  /* Non-empty directory.  */
+  errno = 0;
+  ASSERT (rmdir (BASE "dir") == -1);
+  ASSERT (errno == EEXIST || errno == ENOTEMPTY);
+
+  /* Non-directory.  */
+  errno = 0;
+  ASSERT (rmdir (BASE "dir/file") == -1);
+  ASSERT (errno == ENOTDIR);
+
+  /* Empty directory.  */
+  ASSERT (unlink (BASE "dir/file") == 0);
+  errno = 0;
+  ASSERT (rmdir (BASE "dir/./") == -1);
+  ASSERT (errno == EINVAL || errno == EBUSY);
+  ASSERT (rmdir (BASE "dir") == 0);
+
+  /* Test symlink behavior.  Specifying trailing slash should remove
+     referent directory (POSIX), or cause ENOTDIR failure (Linux), but
+     not touch symlink.  We prefer the Linux behavior for its
+     intuitiveness (especially compared to rmdir("symlink-to-file/")),
+     but not enough to penalize POSIX systems with an rpl_rmdir.  */
+  if (symlink (BASE "dir", BASE "link") != 0)
+    {
+      fputs ("skipping test: symlinks not supported on this filesystem\n",
+             stderr);
+      return 77;
+    }
+  ASSERT (mkdir (BASE "dir", 0700) == 0);
+  errno = 0;
+  if (rmdir (BASE "link/") == 0)
+    {
+      struct stat st;
+      errno = 0;
+      ASSERT (stat (BASE "link", &st) == -1);
+      ASSERT (errno == ENOENT);
+    }
+  else
+    {
+      ASSERT (errno == ENOTDIR);
+      ASSERT (rmdir (BASE "dir") == 0);
+    }
+  ASSERT (unlink (BASE "link") == 0);
+
+  return 0;
+}