-pdu=auto support

diff --git a/examples/sample.makefile.regen b/examples/sample.makefile.regen
index 8c8be63..04b5608 100755
--- a/examples/sample.makefile.regen
+++ b/examples/sample.makefile.regen
@@ -1,9 +1,9 @@
 #!/bin/sh
 
-if [ -z "$ASN1PDU"	\
+if test -z "$ASN1PDU"	\
  -o  -z "$ASN1MODULES"	\
  -o  -z "$PROGNAME"	\
- ]; then
+; then
 	echo "ASN1CMDOPTS=\"$ASN1CMDOPTS\""
 	echo "ASN1MODULES=\"$ASN1MODULES\""
 	echo "ASN1PDU=\"$ASN1PDU\""
@@ -12,18 +12,29 @@
 	exit
 fi
 
+ASN1PDU=`echo "$ASN1PDU" | tr - _`
+
 ../../asn1c/asn1c -S ../../skeletons ${ASN1CMDOPTS} ${ASN1MODULES} || exit $?
 
-if [ ! -f Makefile.am.sample ]; then
+if test ! -f Makefile.am.sample ; then
 	echo "Makefile.am.sample is missing"
 	exit 1
 fi
 
-ASN1PDU=`echo "$ASN1PDU" | tr - _`
+EXTRA_CFLAGS=""
+
+if test -f config.h ; then
+	EXTRA_CFLAGS="$EXTRA_CFLAGS -DHAVE_CONFIG_H"
+fi
+
+FIXEDPDU=`echo "[$ASN1PDU]" | sed -e "s/.*-pdu=auto.*//"`
+if test "$FIXEDPDU" ; then
+	EXTRA_CFLAGS="$EXTRA_CFLAGS -DASN_PDU_COLLECTION"
+fi
 
 set -x
 cat Makefile.am.sample						\
-	| sed -e "s/^CFLAGS.*/CFLAGS += -I. -DHAVE_CONFIG_H -DPDU=${ASN1PDU}/" \
+	| sed -e "s/^CFLAGS.*/CFLAGS += -I. $EXTRA_CFLAGS -DPDU=${ASN1PDU}/" \
 	| sed -e "s/^all: /all: ${ASN1PDU}.c /"			\
 	| sed -e "s/progname/${PROGNAME}/"			\
 	> Makefile.$$