rm: fix the new --dir (-d) option to work with -i

* src/remove.c (prompt): Hoist the computation of is_empty, since we'll
need it slightly earlier.
Before, this function would arrange to fail with EISDIR when processing
a directory without --recursive (-r).  Adjust the condition to exempt
an empty directory when --dir has been specified.
Improve comments.
* tests/rm/d-3: New file, to ensure that rm -d -i dir works.
* tests/Makefile.am (TESTS): Add it.
* NEWS (Bug fixes): Mention it.
* THANKS.in: Update.
Reported by Michael Price in http://bugs.gnu.org/12260

NEWS

@@ -9,6 +9,10 @@ GNU coreutils NEWS                                    -*- outline -*-
   it detects this precise type of cycle, diagnoses it as such and
   eventually exits nonzero.
 
+  rm -i -d now prompts the user then removes an empty directory, rather
+  than ignoring the -d option and failing with an 'Is a directory' error.
+  [bug introduced in coreutils-8.19, with the addition of --dir (-d)]
+
 
 * Noteworthy changes in release 8.19 (2012-08-20) [stable]
 

THANKS.in

@@ -425,6 +425,7 @@ Michael McFarland                   sidlon@yahoo.com
 Michael McLagan                     mmclagan@invlogic.com
 Michael Mol                         mikemol@gmail.com
 Michael Piefel                      piefel@informatik.hu-berlin.de
+Michael Price                       mprice@atl.lmco.com
 Michael Steffens                    michael.steffens@s.netic.de
 Michael Stummvoll                   michael@stummi.org
 Michael Stutz                       stutz@dsl.org

src/remove.c

@@ -190,6 +190,13 @@ prompt (FTS const *fts, FTSENT const *ent, bool is_dir,
   int dirent_type = is_dir ? DT_DIR : DT_UNKNOWN;
   int write_protected = 0;
 
+  bool is_empty = false;
+  if (is_empty_p)
+    {
+      is_empty = is_empty_dir (fd_cwd, filename);
+      *is_empty_p = is_empty ? T_YES : T_NO;
+    }
+
   /* When nonzero, this indicates that we failed to remove a child entry,
      either because the user declined an interactive prompt, or due to
      some other failure, like permissions.  */
@@ -238,7 +245,10 @@ prompt (FTS const *fts, FTSENT const *ent, bool is_dir,
             break;
 
           case DT_DIR:
-            if (!x->recursive)
+             /* Unless we're either deleting directories or deleting
+                recursively, we want to raise an EISDIR error rather than
+                prompting the user  */
+            if ( ! (x->recursive || (x->remove_empty_directories && is_empty)))
               {
                 write_protected = -1;
                 wp_errno = EISDIR;
@@ -254,15 +264,6 @@ prompt (FTS const *fts, FTSENT const *ent, bool is_dir,
           return RM_ERROR;
         }
 
-      bool is_empty;
-      if (is_empty_p)
-        {
-          is_empty = is_empty_dir (fd_cwd, filename);
-          *is_empty_p = is_empty ? T_YES : T_NO;
-        }
-      else
-        is_empty = false;
-
       /* Issue the prompt.  */
       if (dirent_type == DT_DIR
           && mode == PA_DESCEND_INTO_DIR
@@ -420,7 +421,8 @@ rm_fts (FTS *fts, FTSENT *ent, struct rm_options const *x)
         {
           /* This is the first (pre-order) encounter with a directory
              that we cannot delete.
-             Not recursive, so arrange to skip contents.  */
+             Not recursive, and it's not an empty directory (if we're removing
+             them) so arrange to skip contents.  */
           int err = x->remove_empty_directories ? ENOTEMPTY : EISDIR;
           error (0, err, _("cannot remove %s"), quote (ent->fts_path));
           mark_ancestor_dirs (ent);

tests/Makefile.am

@@ -101,6 +101,7 @@ TESTS =						\
   misc/ls-time					\
   rm/d-1					\
   rm/d-2					\
+  rm/d-3					\
   rm/deep-1					\
   rm/deep-2					\
   rm/dir-no-w					\

tests/rm/d-3

@@ -0,0 +1,37 @@
+#!/bin/sh
+# Ensure that 'rm -d -i dir' (i.e., without --recursive) gives a prompt and
+# then deletes the directory if it is empty
+
+# Copyright (C) 2012 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/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ rm
+
+mkdir d || framework_failure_
+
+echo "y" | rm -i -d --verbose d > out 2> out.err || fail=1
+printf "%s" \
+    "rm: remove directory 'd'? " \
+    > exp.err || framework_failure_
+
+printf "%s\n" \
+    "removed directory: 'd'" \
+    > exp || framework_failure_
+
+compare exp out || fail=1
+compare exp.err out.err || fail=1
+
+Exit $fail