Cleanly handle empty return from pg_config --pgxs

On a debian-derivate system, the call may prints on stderr:

" You need to install postgresql-server-dev-X.Y for building
  a server-side extension or libpq-dev for building a client-side
  application. "

This has been seen on a Trisquel 7.0 GNU/Linux system.

git-svn-id: http://svn.osgeo.org/postgis/trunk@14399 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/configure.ac b/configure.ac
index 4ac807368a957b6f025dbb2e573a1a5653325cfa..e99a6ecac68072ee3b818d8c23e78a5748b7b185 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -422,7 +422,7 @@ if test "x$LIBLWGEOM_ONLY" = "xno"; then
   dnl ===========================================================================
 
   PGXS=`$PG_CONFIG --pgxs`
-  if test ! -f $PGXS; then
+  if test "x$PGXS" = "x" -o ! -f "$PGXS"; then
     AC_MSG_ERROR([the PGXS Makefile $PGXS cannot be found. Please install the PostgreSQL server development packages and re-run configure.])
   fi