>From 338ab457344588b4ca305ae6c658e30afee77162 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <address@hidden>
Date: Tue, 4 Oct 2016 13:43:32 +0100
Subject: [PATCH] rm: disallow --n alias for --no-preserve-root

* src/rm.c (LONG_OPTS): Add --no-preserve-root- to make
shortened options ambiguous.
* tests/rm/r-root.sh: Add a test case.
* NEWS: Mention the change in behavior.
Fixes http://bugs.gnu.org/24604
---
 NEWS               | 6 ++++--
 src/rm.c           | 4 ++++
 tests/rm/r-root.sh | 6 ++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index c3554d0..e68de05 100644
--- a/NEWS
+++ b/NEWS
@@ -52,6 +52,8 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** Changes in behavior
 
+  rm no longer accepts shortened variants of the --no-preserve-root option.
+
   seq no longer accepts 0 value as increment, and now also rejects NaN
   values for any argument.
 
@@ -81,8 +83,8 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** New Features
 
-   date now accepts the --debug option, to annotate the parsed date string,
-   display timezone information, and warn about potential misuse.
+  date now accepts the --debug option, to annotate the parsed date string,
+  display timezone information, and warn about potential misuse.
 
 
 * Noteworthy changes in release 8.25 (2016-01-20) [stable]
diff --git a/src/rm.c b/src/rm.c
index 13a5714..11d1a49 100644
--- a/src/rm.c
+++ b/src/rm.c
@@ -48,6 +48,7 @@ enum
   INTERACTIVE_OPTION = CHAR_MAX + 1,
   ONE_FILE_SYSTEM,
   NO_PRESERVE_ROOT,
+  NO_PRESERVE_ROOT_,
   PRESERVE_ROOT,
   PRESUME_INPUT_TTY_OPTION
 };
@@ -66,6 +67,9 @@ static struct option const long_opts[] =
 
   {"one-file-system", no_argument, NULL, ONE_FILE_SYSTEM},
   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
+  /* The following enforces full specification of --no-preserve-root
+     to reduce the chance of users being tricked into specifying --n.  */
+  {"no-preserve-root-", no_argument, NULL, NO_PRESERVE_ROOT_},
   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
 
   /* This is solely for testing.  Do not document.  */
diff --git a/tests/rm/r-root.sh b/tests/rm/r-root.sh
index b98db14..c5f0ef4 100755
--- a/tests/rm/r-root.sh
+++ b/tests/rm/r-root.sh
@@ -211,6 +211,12 @@ for opts in           \
 done
 
 #-------------------------------------------------------------------------------
+# Exercise with --no-preserve to ensure shortened equivalent is not allowed.
+returns_ 1 exercise_rm_r_root --no-preserve / || fail=1
+grep -F "option '--no-preserve' is ambiguous" err || fail=1
+test -f x && fail=1
+
+#-------------------------------------------------------------------------------
 # Exercise "rm -r file1 / file2".
 # Expect a non-Zero exit status representing failure to remove "/",
 # yet 'file1' and 'file2' should be removed.
-- 
2.5.5