--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-08-23  John W. Eaton  <jwe@octave.org>
+
+	* aclocal.m4 (OCTAVE_PROG_SED): Don't clobber value from environment.
+	From: Christian Cornelssen <ccorn@cs.tu-berlin.de>.
+
 2007-08-23  Thomas Weber  <thomas.weber.mail@gmail.com>
 
 	* aclocal.m4 (OCTAVE_PROG_GNUPLOT): Drop check for multiple plot

--- a/aclocal.m4
+++ b/aclocal.m4
@@ -810,54 +810,54 @@
 AC_DEFUN([OCTAVE_PROG_SED],
 [AC_MSG_CHECKING([for a sed that does not truncate output])
 if test -z "$SED"; then
-AC_CACHE_VAL(ac_cv_path_sed,
-[# Loop through the user's path and test for sed and gsed.
-# Then use that list of sed's as ones to test for truncation.
-_AS_PATH_WALK([$PATH],
-  [for ac_prog in sed gsed; do
-    for ac_exec_ext in '' $ac_executable_extensions; do
-      if AS_EXECUTABLE_P(["$as_dir/$ac_prog$ac_exec_ext"]); then
-        _sed_list="$_sed_list $as_dir/$ac_prog$ac_exec_ext"
-      fi
+  AC_CACHE_VAL(ac_cv_path_sed, [
+  # Loop through the user's path and test for sed and gsed.
+  # Then use that list of sed's as ones to test for truncation.
+  _AS_PATH_WALK([$PATH],
+    [for ac_prog in sed gsed; do
+      for ac_exec_ext in '' $ac_executable_extensions; do
+	if AS_EXECUTABLE_P(["$as_dir/$ac_prog$ac_exec_ext"]); then
+	  _sed_list="$_sed_list $as_dir/$ac_prog$ac_exec_ext"
+	fi
+      done
     done
-  done
-  ])
-  AS_TMPDIR(sed)
-  _max=0
-  _count=0
-  # Add /usr/xpg4/bin/sed as it is typically found on Solaris
-  # along with /bin/sed that truncates output.
-  for _sed in $_sed_list /usr/xpg4/bin/sed; do
-    test ! -f ${_sed} && break
-    cat /dev/null > "$tmp/sed.in"
+    ])
+    AS_TMPDIR(sed)
+    _max=0
     _count=0
-    echo $ECHO_N "0123456789$ECHO_C" >"$tmp/sed.in"
-    # Check for GNU sed and select it if it is found.
-    if "${_sed}" --version 2>&1 < /dev/null | egrep '(GNU)' > /dev/null;
-then
-      octave_cv_path_sed=${_sed}
-      break;
-    fi
-    while true; do
-      cat "$tmp/sed.in" "$tmp/sed.in" >"$tmp/sed.tmp"
-      mv "$tmp/sed.tmp" "$tmp/sed.in"
-      cp "$tmp/sed.in" "$tmp/sed.nl"
-      echo >>"$tmp/sed.nl"
-      ${_sed} -e 's/a$//' < "$tmp/sed.nl" >"$tmp/sed.out" || break
-      cmp -s "$tmp/sed.out" "$tmp/sed.nl" || break
-      # 10000 chars as input seems more than enough
-      test $_count -gt 10 && break
-      _count=`expr $_count + 1`
-      if test $_count -gt $_max; then
-        _max=$_count
-        octave_cv_path_sed=$_sed
+    # Add /usr/xpg4/bin/sed as it is typically found on Solaris
+    # along with /bin/sed that truncates output.
+    for _sed in $_sed_list /usr/xpg4/bin/sed; do
+      test ! -f ${_sed} && break
+      cat /dev/null > "$tmp/sed.in"
+      _count=0
+      echo $ECHO_N "0123456789$ECHO_C" >"$tmp/sed.in"
+      # Check for GNU sed and select it if it is found.
+      if "${_sed}" --version 2>&1 < /dev/null | egrep '(GNU)' > /dev/null; then
+	octave_cv_path_sed=${_sed}
+	break;
       fi
+      while true; do
+	cat "$tmp/sed.in" "$tmp/sed.in" >"$tmp/sed.tmp"
+	mv "$tmp/sed.tmp" "$tmp/sed.in"
+	cp "$tmp/sed.in" "$tmp/sed.nl"
+	echo >>"$tmp/sed.nl"
+	${_sed} -e 's/a$//' < "$tmp/sed.nl" >"$tmp/sed.out" || break
+	cmp -s "$tmp/sed.out" "$tmp/sed.nl" || break
+	# 10000 chars as input seems more than enough
+	test $_count -gt 10 && break
+	_count=`expr $_count + 1`
+	if test $_count -gt $_max; then
+	  _max=$_count
+	  octave_cv_path_sed=$_sed
+	fi
+      done
     done
-  done
-  rm -rf "$tmp"
-])
+    rm -rf "$tmp"
+  ])
+  SED=$octave_cv_path_sed
 fi
-AC_SUBST([SED], $octave_cv_path_sed)
+AC_SUBST(SED)
 AC_MSG_RESULT([$SED])
 ])
 dnl