bug-fix for rm on systems that might have unlinkable directories

[Jim Meyering]

On some systems (see unlinkdir.m4[1] for the list), GNU rm takes
advantage of "knowing" that unlink ("directory") will always fail,
and thus avoids a race condition.

However, in all post-6.9 snapshots and in coreutils-6.9.90, the uglier code
that is used only on other systems has a bug that made it impossible to
remove a non-directory as root.

[1] If you know of a system not mentioned in this macro and on which
unlink ("directory") is guaranteed to fail, please tell address@hidden
http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=m4/unlinkdir.m4

Here's the patch:

        "rm" as root would fail to unlink a non-directory on OS X 10.4.x

        * src/remove.c (remove_entry) ["can unlink directories"]: Fix a
        mistakenly reversed condition.
        * NEWS: Mention this bug fix.
        Reported by Pieter Bowman.

---
 ChangeLog    |    8 ++++++++
 NEWS         |    4 ++++
 THANKS       |    1 +
 src/remove.c |    2 +-
 4 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f9686a6..d2f2f31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2007-12-09  Jim Meyering  <address@hidden>
+
+       "rm" as root would fail to unlink a non-directory on OS X 10.4.x
+       * src/remove.c (remove_entry) ["can unlink directories"]: Fix a
+       mistakenly reversed condition.
+       * NEWS: Mention this bug fix.
+       Reported by Pieter Bowman.
+
 2007-12-08  Jim Meyering  <address@hidden>

        * src/c99-to-c89.diff: Adjust shred.c offsets.
diff --git a/NEWS b/NEWS
index c6a0511..e5e59a6 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,10 @@ GNU coreutils NEWS                                    -*- 
outline -*-

 * Noteworthy changes in release 6.9.91 (????-??-??) [beta]

+  "rm" would fail to unlink a non-directory when run in an environment
+  in which the user running rm is capable of unlinking a directory.
+  [bug introduced in coreutils-6.9]
+

 * Noteworthy changes in release 6.9.90 (2007-12-01) [beta]

diff --git a/THANKS b/THANKS
index 0b0124b..f91c262 100644
--- a/THANKS
+++ b/THANKS
@@ -424,6 +424,7 @@ Philippe De Muyter                  address@hidden
 Philippe Schnoebelen                address@hidden
 Phillip Jones                       address@hidden
 Piergiorgio Sartor                  address@hidden
+Pieter Bowman                       address@hidden
 Piotr Kwapulinski                   address@hidden
 Prashant TR                         address@hidden
 Rainer Orth                         address@hidden
diff --git a/src/remove.c b/src/remove.c
index 11e2ccb..de8f5ff 100644
--- a/src/remove.c
+++ b/src/remove.c
@@ -1150,7 +1150,7 @@ remove_entry (int fd_cwd, Dirstack_state const *ds, char 
const *filename,
            dirent_type = DT_DIR;
        }

-      if (dirent_type == DT_DIR)
+      if (dirent_type != DT_DIR)
        {
          /* At this point, barring race conditions, FILENAME is known
             to be a non-directory, so it's ok to try to unlink it.  */
--
1.5.3.7.1116.gae2a9