Improve robustness of mdate-sh script.

* lib/mdate-sh: Sanitize zsh behavior on startup, to ensure
$ls_command is word-split properly upon invocation.
(error): New function.
(main): Use it.  Improve error checking to avoid endless loop
in case $ls_command gave bogus output.  Fix eval quotation.
* tests/mdate6.test: New test, to expose eval quotation error.
* tests/Makefile.am: Update.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

1 files changed, 21 insertions, 2 deletions

diff --git a/lib/mdate-sh b/lib/mdate-sh
index c477512f8..60dc485a3 100755
--- a/lib/mdate-sh
+++ b/lib/mdate-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # Get modification time of a file or directory and pretty-print it.
 
-scriptversion=2010-02-22.21; # UTC
+scriptversion=2010-08-21.06; # UTC
 
 # Copyright (C) 1995, 1996, 1997, 2003, 2004, 2005, 2007, 2009, 2010
 # Free Software Foundation, Inc.
@@ -29,6 +29,15 @@ scriptversion=2010-02-22.21; # UTC
 # bugs to <bug-automake@gnu.org> or send patches to
 # <automake-patches@gnu.org>.
 
+if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
+  emulate sh
+  NULLCMD=:
+  # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
+  # is contrary to our usage.  Disable this feature.
+  alias -g '${1+"$@"}'='"$@"'
+  setopt NO_GLOB_SUBST
+fi
+
 case $1 in
   '')
      echo "$0: No file.  Try \`$0 --help' for more information." 1>&2
@@ -51,6 +60,13 @@ EOF
     ;;
 esac
 
+error ()
+{
+  echo "$0: $1" >&2
+  exit 1
+}
+
+
 # Prevent date giving response in another language.
 LANG=C
 export LANG
@@ -100,6 +116,7 @@ month=
 command=
 until test $month
 do
+  test $# -gt 0 || error "failed parsing \`$ls_command /' output"
   shift
   # Add another shift to the command.
   command="$command shift;"
@@ -119,8 +136,10 @@ do
   esac
 done
 
+test -n "$month" || error "failed parsing \`$ls_command /' output"
+
 # Get the extended ls output of the file or directory.
-set dummy x`eval "$ls_command \"\$save_arg1\""`
+set dummy x`eval "$ls_command \"\\\$save_arg1\""`
 
 # Remove all preceding arguments
 eval $command