--- ac-wrapper-11.sh	2011-10-01 16:26:16.000000000 +0200
+++ ac-wrapper.sh	2011-10-01 16:48:14.000000000 +0200
@@ -29,6 +29,16 @@
 	    "   that would use autom4te."
 fi
 
+
+# Sanitize $0 in order to protect against stupid ways of calling this script
+# such as `sh autoconf` which prevent $0 from being set to a valid path.
+# Since we cannot manipulate $0, use $script instead.
+if [ -x "$0" ]; then
+	script="$0"
+else
+	script=$(which "$0")
+fi
+
 if ! seq 0 0 2>/dev/null 1>&2 ; then #338518
 	seq() {
 		local f l i
@@ -55,14 +65,14 @@
 binary=""
 for v in ${vers} ; do
 	auto_ver=${v%:*}
-	if [ -z "${binary}" ] && [ -x "${0}-${auto_ver}" ] ; then
-		binary="${0}-${auto_ver}"
+	if [ -z "${binary}" ] && [ -x "${script}-${auto_ver}" ] ; then
+		binary="${script}-${auto_ver}"
 	fi
 done
 if [ -z "${binary}" ] ; then
 	err "Unable to locate any usuable version of autoconf.\n" \
 	    "\tI tried these versions: ${vers}\n" \
-	    "\tWith a base name of '${0}'."
+	    "\tWith a base name of '${script}'."
 fi
 
 #
@@ -80,8 +90,8 @@
 		auto_ver=${v%:*}
 		want_ver=${v#*:}
 		for wx in ${WANT_AUTOCONF} ; do
-			if [ "${wx}" = "${want_ver}" ] && [ -x "${0}-${auto_ver}" ] ; then
-				binary="${0}-${auto_ver}"
+			if [ "${wx}" = "${want_ver}" ] && [ -x "${script}-${auto_ver}" ] ; then
+				binary="${script}-${auto_ver}"
 				v="x"
 			fi
 		done
@@ -94,8 +104,8 @@
 #
 acprereq_version() {
 	gawk \
-	'($0 !~ /^[[:space:]]*(#|dnl)/) {
-		if (match($0, "AC_PREREQ\\(\\[?([0-9]\\.[0-9])", res))
+	'($script !~ /^[[:space:]]*(#|dnl)/) {
+		if (match($script, "AC_PREREQ\\(\\[?([0-9]\\.[0-9])", res))
 			VERSIONS[COUNT++] = res[1]
 	}
 
@@ -108,7 +118,7 @@
 generated_version() {
 	gawk \
 	'{
-		if (match($0,
+		if (match($script,
 		          "^# Generated (by (GNU )?Autoconf|automatically using autoconf version) ([0-9].[0-9])",
 		          res)) {
 			print res[3]
@@ -140,7 +150,7 @@
 			&& confversion=$(generated_version configure)
 
 		if [ "${confversion}" = "2.1" ] && [ ! -f "configure.ac" ] ; then
-			binary="${0}-2.13"
+			binary="${script}-2.13"
 		fi
 	esac
 fi
@@ -158,7 +168,7 @@
 for v in ${vers} ; do
 	auto_ver=${v%:*}
 	want_ver=${v#*:}
-	if [ "${binary}" = "${0}-${auto_ver}" ] ; then
+	if [ "${binary}" = "${script}-${auto_ver}" ] ; then
 		export WANT_AUTOCONF="${want_ver}"
 	fi
 done