2006-10-09  Paul Eggert  <address@hidden>
	and Stepan Kasal  <address@hidden>

	* lib/install-sh (posix_mkdir): Reject FreeBSD 6.1 mkdir -p -m,
	which incorrectly sets the mode of an existing destination
	directory.  In some cases the unpatched install-sh could do the
	equivalent of "chmod 777 /" or "chmod 0 /" on a buggy FreeBSD
	system.  We hope this is rare in practice, but it's clearly worth
	fixing.  Problem reported by Alex in
	<http://lists.gnu.org/archive/html/bug-autoconf/2006-10/msg00012.html>.

Index: lib/install-sh
===================================================================
RCS file: /cvs/automake/automake/lib/install-sh,v
retrieving revision 1.35
diff -u -r1.35 install-sh
--- lib/install-sh	9 Jul 2006 16:09:31 -0000	1.35
+++ lib/install-sh	10 Oct 2006 09:03:38 -0000
@@ -336,12 +336,27 @@
 	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
 
 	    if (umask $mkdir_umask &&
-		exec $mkdirprog $mkdir_mode -p -- / "$tmpdir/d") >/dev/null 2>&1
+		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
 	    then
-	      # Check for bugs in HP-UX 11.23 and IRIX 6.5 mkdir.
-	      case `ls -ld "$tmpdir"` in
-		d????-??-* ) posix_mkdir=:;;
-	      esac
+	      if test -z "$mkdir_mode"; then
+		posix_mkdir=:
+	      else
+		# Check for POSIX incompatibilities of -m.
+		# FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+		# HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+		# other-writeable bit of parent directory when it shouldn't.
+		ls_ld_tmpdir=`ls -ld "$tmpdir"`
+		case $ls_ld_tmpdir in
+		  d????-?r-*) different_mode=700;;
+		  d????-?--*) different_mode=755;;
+		  *) false;;
+		esac &&
+		  $mkdirprog -m $different_mode -p -- "$tmpdir" && {
+		    ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
+		    test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+		  } &&
+		  posix_mkdir=:
+	      fi
 	      rmdir "$tmpdir/d" "$tmpdir"
 	    else
 	      # Remove any dirs left behind by ancient mkdir implementations.