Index: /trunk/src/VBox/HostServices/SharedFolders/vbsfpathabs.cpp
===================================================================
--- /trunk/src/VBox/HostServices/SharedFolders/vbsfpathabs.cpp	(revision 78113)
+++ /trunk/src/VBox/HostServices/SharedFolders/vbsfpathabs.cpp	(revision 78114)
@@ -185,4 +185,6 @@
     /* Fallback for the common paths. */
 
-    return RTPathAbsEx(pszRoot, pszPath, RTPATH_STR_F_STYLE_HOST, pszAbsPath, &cbAbsPath);
+    if (*pszPath != '\0')
+        return RTPathAbsEx(pszRoot, pszPath, RTPATH_STR_F_STYLE_HOST, pszAbsPath, &cbAbsPath);
+    return RTPathAbsEx(NULL, pszRoot, RTPATH_STR_F_STYLE_HOST, pszAbsPath, &cbAbsPath);
 }