improve unlink on Solaris

[Eric Blake]

I'm working on a patch to fix unlink("file/") on Solaris 9.  But as a 
prerequisite (to avoid anyone corrupting their file system if running the unit 
test as root, and accidentally unlinking an empty directory), I noticed that 
mingw failed to compile unlinkdir.c due to a missing geteuid.  This works 
around it:


From: Eric Blake <address@hidden>
Date: Wed, 16 Sep 2009 17:18:28 -0600
Subject: [PATCH] unlinkdir: port to mingw

* m4/unlinkdir.m4 (gl_UNLINKDIR): Add mingw to list of platforms
that refuse anyone to unlink a directory.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog       |    6 ++++++
 m4/unlinkdir.m4 |    5 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ff11ebe..1b30e94 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2009-09-16  Eric Blake  <address@hidden>

+       unlinkdir: port to mingw
+       * m4/unlinkdir.m4 (gl_UNLINKDIR): Add mingw to list of platforms
+       that refuse anyone to unlink a directory.
+
+2009-09-16  Eric Blake  <address@hidden>
+
        remove: new module
        * modules/remove: New file.
        * lib/remove.c: Likewise.
diff --git a/m4/unlinkdir.m4 b/m4/unlinkdir.m4
index 0c84375..a8256d1 100644
--- a/m4/unlinkdir.m4
+++ b/m4/unlinkdir.m4
@@ -16,7 +16,7 @@ AC_DEFUN([gl_UNLINKDIR],
   AC_LIBOBJ([unlinkdir])

   # The Hurd, the Linux kernel, the FreeBSD kernel version 2.2 and later,
-  # and Cygwin never let anyone (even root) unlink directories.
+  # Cygwin, and mingw never let anyone (even root) unlink directories.
   # If anyone knows of another system for which unlink can never
   # remove a directory, please report it to <address@hidden>.
   # Unfortunately this is difficult to test for, since it requires root access
@@ -26,7 +26,8 @@ AC_DEFUN([gl_UNLINKDIR],
   *-*-gnu[[0-9]]* | \
   *-*-linux-* | *-*-linux | \
   *-*-freebsd2.2* | *-*-freebsd[[3-9]]* | *-*-freebsd[[1-9]][[0-9]]* | \
-  *-cygwin)
+  *-cygwin | \
+  *-mingw)
     AC_DEFINE([UNLINK_CANNOT_UNLINK_DIR], [1],
       [Define to 1 if unlink (dir) cannot possibly succeed.]);;
   esac
-- 
1.6.4.2