diff --git a/openide.filesystems/src/org/openide/filesystems/NbfsUtil.java b/openide.filesystems/src/org/openide/filesystems/NbfsUtil.java
--- a/openide.filesystems/src/org/openide/filesystems/NbfsUtil.java
+++ b/openide.filesystems/src/org/openide/filesystems/NbfsUtil.java
@@ -42,9 +42,9 @@
 package org.openide.filesystems;
 
 import java.io.UnsupportedEncodingException;
+import java.net.URI;
 import java.net.URL;
 import java.net.URLDecoder;
-import java.net.URLEncoder;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
@@ -57,6 +57,8 @@
 final class NbfsUtil {
     /** url separator */
     private static final char SEPARATOR = '/';
+    /** old host name field prior to #39613 */
+    private static final String HOST = "nbhost"; // NOI18N
 
     /**
      * Gets URL with nbfs protocol for passes fo
@@ -64,13 +66,7 @@
      * @return url with nbfs protocol
      * @throws FileStateInvalidException if FileObject somehow corrupted
      */
-    static URL getURL(FileObject fo) throws FileStateInvalidException {
-        final String fsPart = encodeFsPart(fo);
-        final String foPart = encodeFoPart(fo);
-
-        final String host = "nbhost"; //NOI18N
-        final String file = combine(fsPart, foPart);
-
+    static URL getURL(final FileObject fo) throws FileStateInvalidException {
         // #13038: the URL constructor accepting a handler is a security-sensitive
         // operation. Sometimes a user class loaded internally (customized bean...),
         // which has no privileges, needs to make and use an nbfs: URL, since this
@@ -79,8 +75,7 @@
             return AccessController.doPrivileged(
                 new PrivilegedExceptionAction<URL>() {
                     public URL run() throws Exception {
-                        // #30397: the fsPart name cannot be null
-                        return new URL(FileURL.PROTOCOL, host, -1, file, new FileURL.Handler());
+                        return new URI(FileURL.PROTOCOL, fo.getFileSystem().getSystemName(), "/" + fo.getPath(), null).toURL();
                     }
                 }
             );
@@ -92,14 +87,6 @@
         }
     }
 
-    private static String combine(final String host, final String file) {
-        StringBuffer sb = new StringBuffer();
-        sb.append(SEPARATOR).append(host);
-        sb.append(file);
-
-        return sb.toString();
-    }
-
     private static String[] split(URL url) {
         String file = url.getFile();
         int idx = file.indexOf("/", 1);
@@ -125,45 +112,28 @@
             return null;
         }
 
-        if (isOldEncoding(url)) {
+        String host = url.getHost();
+
+        if (host == null || host.length() == 0) {
             return oldDecode(url);
         }
 
-        String[] urlParts = split(url);
+        String fsName, foName;
+        if (host.equals(HOST)) {
+            String[] urlParts = split(url);
 
-        String fsName = decodeFsPart(urlParts[0]);
-        String foName = decodeFoPart(urlParts[1]);
+            fsName = decodeFsPart(urlParts[0]);
+            foName = decodeFoPart(urlParts[1]);
+        } else {
+            fsName = host;
+            foName = url.getPath().substring(1);
+        }
 
         FileSystem fsys = Repository.getDefault().findFileSystem(fsName);
 
         return (fsys == null) ? null : fsys.findResource(foName);
     }
 
-    private static String encodeFsPart(FileObject fo) throws FileStateInvalidException {
-        FileSystem fs = fo.getFileSystem();
-
-        return encoder(fs.getSystemName());
-    }
-
-    private static String encodeFoPart(FileObject fo) {
-        StringTokenizer elemsEnum;
-        StringBuffer sBuff = new StringBuffer();
-        elemsEnum = new StringTokenizer(fo.getPath(), String.valueOf(SEPARATOR));
-
-        while (elemsEnum.hasMoreElements()) {
-            sBuff.append(SEPARATOR);
-            sBuff.append(encoder((String) elemsEnum.nextElement()));
-        }
-
-        String retVal = sBuff.toString();
-
-        if ((retVal.length() == 0) || (fo.isFolder() && (retVal.charAt(retVal.length() - 1) != SEPARATOR))) {
-            retVal += SEPARATOR;
-        }
-
-        return retVal;
-    }
-
     private static String decodeFsPart(String encodedStr) {
         return decoder(encodedStr);
     }
@@ -185,14 +155,6 @@
         return sBuff.toString();
     }
 
-    private static String encoder(String elem) {
-        try {
-            return URLEncoder.encode(elem, "UTF-8"); // NOI18N
-        } catch (UnsupportedEncodingException e) {
-            throw new AssertionError(e);
-        }
-    }
-
     private static String decoder(String elem) {
         try {
             return URLDecoder.decode(elem, "UTF-8"); // NOI18N
@@ -201,13 +163,6 @@
         }
     }
 
-    // backward compatibility
-    private static boolean isOldEncoding(URL url) {
-        String host = url.getHost();
-
-        return (host == null) || (host.length() == 0);
-    }
-
     private static FileObject oldDecode(URL u) {
         String resourceName = u.getFile();
 
diff --git a/openide.filesystems/src/org/openide/filesystems/XMLFileSystem.java b/openide.filesystems/src/org/openide/filesystems/XMLFileSystem.java
--- a/openide.filesystems/src/org/openide/filesystems/XMLFileSystem.java
+++ b/openide.filesystems/src/org/openide/filesystems/XMLFileSystem.java
@@ -330,7 +330,7 @@
         Handler handler = new Handler(DTD_MAP, rootElem = new ResourceElem(true, urls, null), validate); // NOI18N        
 
         try {
-            _setSystemName("XML_" + urls[0].toExternalForm().replace('/','-')); // NOI18N
+            _setSystemName(urls[0].toExternalForm());
         } catch (PropertyVetoException pvx) {
             rootElem = null;
             throw pvx;
diff --git a/openide.filesystems/test/unit/src/org/openide/filesystems/FileObjectTestHid.java b/openide.filesystems/test/unit/src/org/openide/filesystems/FileObjectTestHid.java
--- a/openide.filesystems/test/unit/src/org/openide/filesystems/FileObjectTestHid.java
+++ b/openide.filesystems/test/unit/src/org/openide/filesystems/FileObjectTestHid.java
@@ -2727,6 +2727,7 @@
         assertNotNull("had a URL for " + f1, u1);
         URI uri1 = new URI(u1.toExternalForm());
         String path1 = uri1.getPath();
+        System.err.println("XXX u1=" + u1 + " uri1=" + uri1 + " path1=" + path1);
         if (path1 != null) {
             assertTrue("path of " + uri1 + " ends with /", path1.endsWith("/"));
             String path2 = path1 + f2.getNameExt();