# HG changeset patch
# Parent cf1bbd7899119a0651f0a5ac0c5c2b65a422e1d6

diff --git a/openide.loaders/apichanges.xml b/openide.loaders/apichanges.xml
--- a/openide.loaders/apichanges.xml
+++ b/openide.loaders/apichanges.xml
@@ -109,6 +109,23 @@
 <!-- ACTUAL CHANGES BEGIN HERE: -->
 
   <changes>
+      <change id="DataShadow.findOriginal">
+          <api name="loaders"/>
+          <summary>
+              Introduced <code>DataShadow.findOriginal</code> which extracts the original file from
+              a FileObject representing a shadow/link.
+          </summary>
+          <version major="7" minor="42"/>
+          <date day="22" month="11" year="2012"/>
+          <author login="sdedic"/>
+          <compatibility addition="yes"/>
+          <description>
+              Target FileObject can be obtained, instead of DataObject. The target may be invalid,
+              or otherwise unsuitable for DataObject creation. Use this method to just dereference
+              the shadow file.
+          </description>
+          <class package="org.openide.loaderss" name="DataShadow"/>
+      </change>
       <change id="DataObjec.Registration">
           <api name="loaders"/>
           <summary>Introduced <code>DataObject.Registration</code> and <code>DataObject.Registrations</code></summary>
diff --git a/openide.loaders/manifest.mf b/openide.loaders/manifest.mf
--- a/openide.loaders/manifest.mf
+++ b/openide.loaders/manifest.mf
@@ -1,6 +1,6 @@
 Manifest-Version: 1.0
 OpenIDE-Module: org.openide.loaders
-OpenIDE-Module-Specification-Version: 7.41
+OpenIDE-Module-Specification-Version: 7.42
 OpenIDE-Module-Localizing-Bundle: org/openide/loaders/Bundle.properties
 OpenIDE-Module-Provides: org.netbeans.modules.templates.v1_0
 OpenIDE-Module-Layer: org/netbeans/modules/openide/loaders/layer.xml
diff --git a/openide.loaders/src/org/openide/loaders/DataShadow.java b/openide.loaders/src/org/openide/loaders/DataShadow.java
--- a/openide.loaders/src/org/openide/loaders/DataShadow.java
+++ b/openide.loaders/src/org/openide/loaders/DataShadow.java
@@ -391,17 +391,19 @@
     }
     
     /**
-     * Tries to load the original file from a shadow.
+     * Tries to locate the original file from a shadow.
      * Looks for file contents as well as the originalFile/originalFileSystem attributes.
-     * Attempts to discover locations for migrated files in configuration.
+     * Attempts to discover locations for migrated files in configuration. Returns
+     * {@code null}, if the target file could not be found (broken link)
      * 
      * @param fileObject a data shadow
-     * @return the original <code>DataObject</code> referenced by the shadow
-     * @throws IOException error during load or broken link
+     * @return the original <code>FileObject</code> referenced by the shadow
+     * @throws IOException error during load 
      * 
      * @see Utilities#translate
+     * @since 7.42
      */
-    protected static DataObject deserialize(FileObject fileObject) throws IOException {
+    public static FileObject findOriginal(FileObject fileObject) throws IOException {
         String[] fileAndFileSystem = readOriginalFileAndFileSystem(fileObject);
         String path = fileAndFileSystem[0];
         assert path != null;
@@ -465,12 +467,31 @@
                 }
             }
         }
+        return target;
+    }
+    
+    /**
+     * Tries to load the original file from a shadow.
+     * Looks for file contents as well as the originalFile/originalFileSystem attributes.
+     * Attempts to discover locations for migrated files in configuration.
+     * 
+     * @param fileObject a data shadow
+     * @return the original <code>DataObject</code> referenced by the shadow
+     * @throws IOException error during load or broken link
+     * 
+     * @see Utilities#translate
+     */
+    protected static DataObject deserialize(FileObject fileObject) throws IOException {
+        FileObject target = findOriginal(fileObject);
         if (target != null) {
             return DataObject.find(target);
         } else {
-            throw new FileNotFoundException(path + ':' + fsname);
+            String[] fileAndFileSystem = readOriginalFileAndFileSystem(fileObject);
+            String path = fileAndFileSystem[0];
+            throw new FileNotFoundException(path + ':' + fileAndFileSystem[1]);
         }
     }
+    
     static URL readURL(FileObject fileObject) throws IOException {
         String[] fileAndFileSystem = readOriginalFileAndFileSystem(fileObject);
         String path = fileAndFileSystem[0];
diff --git a/openide.loaders/test/unit/src/org/openide/loaders/DataShadowTest.java b/openide.loaders/test/unit/src/org/openide/loaders/DataShadowTest.java
--- a/openide.loaders/test/unit/src/org/openide/loaders/DataShadowTest.java
+++ b/openide.loaders/test/unit/src/org/openide/loaders/DataShadowTest.java
@@ -437,4 +437,46 @@
         R action = new R();
         FileUtil.runAtomicAction(action);
     }
+    
+    /**
+     * Tests the method findOriginal()
+     * @throws Exception 
+     */
+    public void testFindOriginal() throws Exception {
+        FileSystem fs = FileUtil.createMemoryFileSystem();
+        FileObject orig = FileUtil.createData(fs.getRoot(), "path/to/orig");
+        FileObject shadow = FileUtil.createData(fs.getRoot(), "link.shadow");
+        shadow.setAttribute("originalFile", "path/to/orig");
+        assertEquals("found the right original file", 
+                orig, DataShadow.findOriginal(shadow));
+    }
+    
+    /**
+     * Checks that findOriginal returns null on broken (but formally
+     * correct) shadow
+     * @throws Exception C
+     */
+    public void testFindMissingOriginal() throws Exception {
+        FileSystem fs = FileUtil.createMemoryFileSystem();
+        FileObject shadow = FileUtil.createData(fs.getRoot(), "link.shadow");
+        shadow.setAttribute("originalFile", "path/to/orig");
+        assertNull("null should be returned for missing target", DataShadow.findOriginal(shadow));
+    }
+    
+    /**
+     * Checks that findOriginal throws Exception on a malformed 
+     * shadow
+     * @throws Exception 
+     */
+    public void testFindBrokenOriginal() throws Exception {
+        FileSystem fs = FileUtil.createMemoryFileSystem();
+        FileObject orig = FileUtil.createData(fs.getRoot(), "path/to/orig");
+        FileObject shadow = FileUtil.createData(fs.getRoot(), "link.shadow");
+        try {
+            DataShadow.findOriginal(shadow);
+            fail("IOException should be thrown on malformed shadow");
+        } catch (IOException ex) {
+            // this is oK
+        }
+    }
 }