Detect VRT_DirectorResolve in varnish-cache

configure.ac

@@ -26,6 +26,12 @@ AC_CONFIG_FILES([
 	src/Makefile
 ])
 
+save_CFLAGS="${CFLAGS}"
+CFLAGS="${VARNISHAPI_CFLAGS}"
+AC_CHECK_DECLS([VRT_DirectorResolve], [], [], [[#include "vdef.h"
+		#include "vrt.h"]])
+CFLAGS="${save_CFLAGS}"
+
 AC_OUTPUT
 
 AS_ECHO("

src/vmod_cluster.c

@@ -42,7 +42,7 @@
  * workaround missing VRT_DirectorResolve
  * Ref https://github.com/varnishcache/varnish-cache/pull/2680
  */
-
+#ifndef HAVE_DECL_VRT_DIRECTORRESOLVE
 #include <cache/cache_director.h>
 
 static VCL_BACKEND
@@ -60,7 +60,7 @@ VRT_DirectorResolve(VRT_CTX, VCL_BACKEND d)
 		AN(d->vdir);
 	return (d);
 }
-
+#endif
 /* ------------------------------------------------------------
  */