Fix so custom --with-projdir= configure switch works again.

Closes #4279 for PostGIS 2.3

git-svn-id: http://svn.osgeo.org/postgis/branches/2.3@17121 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/configure.ac b/configure.ac
index dfb1a05e60eeb01749427b474ccca164302674f7..413d418976782cb0c77c52a1a9bdf8259793983d 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -812,6 +812,8 @@ if test ! "x$PROJDIR" = "x"; then
 fi
 
 dnl Check that we can find the proj_api.h header file
+CPPFLAGS_SAVE="$CPPFLAGS"
+CPPFLAGS="$PROJ_CPPFLAGS"
 AC_CHECK_HEADER([proj_api.h], [], [AC_MSG_ERROR([could not find proj_api.h - you may need to specify the directory of a PROJ.4 installation using --with-projdir])],
 [
 #define ACCEPT_USE_OF_DEPRECATED_PROJ_API_H 1