fixes #1

configure

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for units 0.6-0.
+# Generated by GNU Autoconf 2.69 for units 0.6-1.
 #
 # Report bugs to <edzer.pebesma@uni-muenster.de>.
 #
@@ -580,8 +580,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='units'
 PACKAGE_TARNAME='units'
-PACKAGE_VERSION='0.6-0'
-PACKAGE_STRING='units 0.6-0'
+PACKAGE_VERSION='0.6-1'
+PACKAGE_STRING='units 0.6-1'
 PACKAGE_BUGREPORT='edzer.pebesma@uni-muenster.de'
 PACKAGE_URL=''
 
@@ -1244,7 +1244,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures units 0.6-0 to adapt to many kinds of systems.
+\`configure' configures units 0.6-1 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1306,7 +1306,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of units 0.6-0:";;
+     short | recursive ) echo "Configuration of units 0.6-1:";;
    esac
   cat <<\_ACEOF
 
@@ -1395,7 +1395,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-units configure 0.6-0
+units configure 0.6-1
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1789,7 +1789,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by units $as_me 0.6-0, which was
+It was created by units $as_me 0.6-1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -3799,6 +3799,8 @@ if test "${ac_cv_lib_expat_XML_ParserCreate}" == yes; then
    LIBS="${LIBS} -lexpat"
 fi
 
+CPPFLAGS="${UD_CPPFLAGS} ${CPPFLAGS}"
+
 ac_fn_cxx_check_header_mongrel "$LINENO" "udunits2.h" "ac_cv_header_udunits2_h" "$ac_includes_default"
 if test "x$ac_cv_header_udunits2_h" = xyes; then :
 
@@ -4430,7 +4432,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by units $as_me 0.6-0, which was
+This file was extended by units $as_me 0.6-1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -4483,7 +4485,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-units config.status 0.6-0
+units config.status 0.6-1
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 

configure.ac

@@ -49,6 +49,8 @@ if test "${ac_cv_lib_expat_XML_ParserCreate}" == yes; then
    LIBS="${LIBS} -lexpat"
 fi
 
+CPPFLAGS="${UD_CPPFLAGS} ${CPPFLAGS}"
+
 AC_CHECK_HEADER(udunits2.h, [], [
 AC_CHECK_HEADER(udunits2/udunits2.h, 
                 UD_CPPFLAGS="${UD_CPPFLAGS} -I/usr/include/udunits2",