8362429: AssertionError in File.listFiles(FileFilter | FilenameFilter)

Reviewed-by: alanb

src/java.base/share/classes/java/io/File.java

@@ -1134,15 +1134,9 @@ public class File
         if (ss == null) return null;
         int n = ss.length;
         File[] fs = new File[n];
-        if (path.isEmpty()) {
-            for (int i = 0; i < n; i++) {
-                fs[i] = new File(ss[i]);
-            }
-        } else {
-            for (int i = 0; i < n; i++) {
-                fs[i] = new File(ss[i], this);
-            }
-        }
+        boolean isEmpty = path.isEmpty();
+        for (int i = 0; i < n; i++)
+            fs[i] = isEmpty ? new File(ss[i]) : new File(ss[i], this);
         return fs;
     }
 
@@ -1175,9 +1169,10 @@ public class File
         String[] ss = normalizedList();
         if (ss == null) return null;
         ArrayList<File> files = new ArrayList<>();
+        boolean isEmpty = path.isEmpty();
         for (String s : ss)
             if ((filter == null) || filter.accept(this, s))
-                files.add(new File(s, this));
+                files.add(isEmpty ? new File(s) : new File(s, this));
         return files.toArray(new File[files.size()]);
     }
 
@@ -1208,8 +1203,9 @@ public class File
         String[] ss = normalizedList();
         if (ss == null) return null;
         ArrayList<File> files = new ArrayList<>();
+        boolean isEmpty = path.isEmpty();
         for (String s : ss) {
-            File f = new File(s, this);
+            File f = isEmpty ? new File(s) : new File(s, this);
             if ((filter == null) || filter.accept(f))
                 files.add(f);
         }

test/jdk/java/io/File/EmptyPath.java

@@ -22,15 +22,18 @@
  */
 
 /* @test
- * @bug 4842706 8024695 8361587
+ * @bug 4842706 8024695 8361587 8362429
  * @summary Test some file operations with empty path
  * @run junit EmptyPath
  */
 
 import java.io.File;
+import java.io.FileFilter;
 import java.io.FileInputStream;
+import java.io.FilenameFilter;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.net.MalformedURLException;
 import java.nio.file.Files;
 import java.nio.file.FileStore;
 import java.nio.file.Path;
@@ -38,6 +41,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import org.junit.jupiter.api.BeforeAll;
@@ -211,7 +215,15 @@ public class EmptyPath {
 
     @Test
     public void list() throws IOException {
-        String[] files = f.list();
+        list(f.list());
+    }
+
+    @Test
+    public void listFilenameFilter() throws IOException {
+        list(f.list((FilenameFilter)null));
+    }
+
+    private void list(String[] files) throws IOException {
         assertNotNull(files);
         Set<String> ioSet = new HashSet(Arrays.asList(files));
         Set<String> nioSet = new HashSet();
@@ -221,11 +233,42 @@ public class EmptyPath {
 
     @Test
     public void listFiles() throws IOException {
-        File child = new File(f.getAbsoluteFile(), "child");
+        listFiles(x -> x.listFiles());
+    }
+
+    @Test
+    public void listFilesFileFilter() throws IOException {
+        FileFilter ff = new FileFilter() {
+            public boolean accept(File pathname) { return true; }
+        };
+        listFiles(x -> x.listFiles(ff));
+    }
+
+    @Test
+    public void listFilesNullFileFilter() throws IOException {
+        listFiles(x -> x.listFiles((FileFilter)null));
+    }
+
+    @Test
+    public void listFilesFilenameFilter() throws IOException {
+        FilenameFilter fnf = new FilenameFilter() {
+            public boolean accept(File dir, String name) { return true; }
+        };
+        listFiles(x -> x.listFiles(fnf));
+    }
+
+    @Test
+    public void listFilesNullFilenameFilter() throws IOException {
+        listFiles(x -> x.listFiles((FilenameFilter)null));
+    }
+
+    private void listFiles(Function<File,File[]> func) throws IOException {
+        String childName = "child" + System.nanoTime();
+        File child = new File(f.getAbsoluteFile(), childName);
         assertTrue(child.createNewFile());
         child.deleteOnExit();
 
-        File[] files = f.listFiles();
+        File[] files = func.apply(f);
         for (File file : files)
             assertEquals(-1, f.toString().indexOf(File.separatorChar));
 
@@ -348,4 +391,9 @@ public class EmptyPath {
     public void toURI() {
         assertEquals(f.toPath().toUri(), f.toURI());
     }
+
+    @Test
+    public void toURL() throws MalformedURLException {
+        assertEquals(f.toPath().toUri().toURL(), f.toURL());
+    }
 }