* src/copy.c (copy_internal): Don't make a backup if the last

component of the source name is "." or "..".
Reported by Andreas Schwab in https://savannah.gnu.org/bugs/?17540.
* tests/cp/src-base-dot: New file.  Test for the above fix.
* tests/cp/Makefile.am (TESTS): Add src-base-dot.

ChangeLog

@@ -1,5 +1,11 @@
 2006-08-27  Jim Meyering  <jim@meyering.net>
 
+	* src/copy.c (copy_internal): Don't make a backup if the last
+	component of the source name is "." or "..".
+	Reported by Andreas Schwab in https://savannah.gnu.org/bugs/?17540.
+	* tests/cp/src-base-dot: New file.  Test for the above fix.
+	* tests/cp/Makefile.am (TESTS): Add src-base-dot.
+
 	* src/system.h (DOT_OR_DOTDOT): Remove macro.  Rewrite as a...
 	(dot_or_dotdot): ...new static inline function.
 	* src/remove.c (rm_1): Reflect this renaming.

src/copy.c

@@ -1185,7 +1185,10 @@ copy_internal (char const *src_name, char const *dst_name,
 		}
 	    }
 
-	  if (x->backup_type != no_backups)
+	  if (x->backup_type != no_backups
+	      /* Don't try to back up a destination if the last
+		 component of src_name is "." or "..".  */
+	      && ! dot_or_dotdot (last_component (src_name)))
 	    {
 	      char *tmp_backup = find_backup_file_name (dst_name,
 							x->backup_type);

tests/cp/Makefile.am

@@ -21,6 +21,7 @@
 AUTOMAKE_OPTIONS = 1.1 gnits
 
 TESTS = \
+  src-base-dot \
   sparse \
   link-no-deref \
   cp-deref \

tests/cp/src-base-dot

@@ -0,0 +1,54 @@
+#!/bin/sh
+# Ensure that "mkdir x y; cd y; cp -ab ../x/. ." is a successful, silent, no-op.
+
+# Copyright (C) 2006 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 2 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, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  cp --version
+fi
+
+. $srcdir/../envvar-check
+
+pwd=`pwd`
+t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
+trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; rm -rf $t0 && exit $status' 0
+trap '(exit $?); exit $?' 1 2 13 15
+
+framework_failure=0
+mkdir -p $tmp || framework_failure=1
+cd $tmp || framework_failure=1
+
+mkdir x y || framework_failure=1
+
+if test $framework_failure = 1; then
+  echo "$0: failure in testing framework" 1>&2
+  (exit 1); exit 1
+fi
+
+fail=0
+
+cd y
+cp --verbose -ab ../x/. . > out 2>&1 || fail=1
+cat <<\EOF > exp || fail=1
+EOF
+
+cmp out exp || fail=1
+test $fail = 1 && diff out exp 2> /dev/null
+
+(exit $fail); exit $fail