--- a/jdk/src/share/back/transport.c	Tue Mar 05 11:49:33 2013 -0800
+++ b/jdk/src/share/back/transport.c	Tue Mar 05 19:25:35 2013 +0100
@@ -117,6 +117,9 @@
 
     /* Construct library name (simple name or full path) */
     dbgsysBuildLibName(libname, sizeof(libname), plibdir, name);
+    if (strlen(libname) == 0) {
+        return NULL;
+    }
 
     /* dlopen (unix) / LoadLibrary (windows) the transport library */
     handle = dbgsysLoadLibrary(libname, buf, sizeof(buf));