8296878: Document Filter attached to JPasswordField and setText("") is not cleared instead inserted characters replaced with unicode null characters

Reviewed-by: prr, aivanov

src/java.desktop/share/classes/javax/swing/JPasswordField.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -36,8 +36,10 @@ import javax.accessibility.AccessibleContext;
 import javax.accessibility.AccessibleRole;
 import javax.accessibility.AccessibleText;
 import javax.accessibility.AccessibleTextSequence;
+import javax.swing.text.AbstractDocument;
 import javax.swing.text.BadLocationException;
 import javax.swing.text.Document;
+import javax.swing.text.DocumentFilter;
 import javax.swing.text.Segment;
 
 /**
@@ -300,21 +302,27 @@ public class JPasswordField extends JTextField {
     public void setText(String t) {
         // overwrite the old data first
         Document doc = getDocument();
-        int nleft = doc.getLength();
-        Segment text = new Segment();
-        // we would like to get direct data array access, not a copy of it
-        text.setPartialReturn(true);
-        int offs = 0;
-        try {
-            while (nleft > 0) {
-                doc.getText(offs, nleft, text);
-                Arrays.fill(text.array, text.offset,
-                            text.count + text.offset, '\u0000');
-                nleft -= text.count;
-                offs += text.count;
+        DocumentFilter filter = null;
+        if (doc instanceof AbstractDocument adoc) {
+            filter = adoc.getDocumentFilter();
+        }
+        if (filter == null) {
+            int nleft = doc.getLength();
+            Segment text = new Segment();
+            // we would like to get direct data array access, not a copy of it
+            text.setPartialReturn(true);
+            int offs = 0;
+            try {
+                while (nleft > 0) {
+                    doc.getText(offs, nleft, text);
+                    Arrays.fill(text.array, text.offset,
+                                text.count + text.offset, '\u0000');
+                    nleft -= text.count;
+                    offs += text.count;
+                }
+            } catch (BadLocationException ignored) {
+                // we tried
             }
-        } catch (BadLocationException ignored) {
-            // we tried
         }
         super.setText(t);
     }

test/jdk/javax/swing/JPasswordField/OldPasswordInDocumentFilter.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.awt.EventQueue;
+import java.util.Arrays;
+
+import javax.swing.JPasswordField;
+import javax.swing.text.AttributeSet;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Document;
+import javax.swing.text.DocumentFilter;
+import javax.swing.text.PlainDocument;
+
+/**
+ * @test
+ * @bug 8296878
+ * @summary can the old password be accessed in the DocumentFilter
+ */
+public final class OldPasswordInDocumentFilter {
+
+    public static void main(String[] args) throws Exception {
+        EventQueue.invokeAndWait(OldPasswordInDocumentFilter::test);
+    }
+
+    private static void test() {
+        JPasswordField test = new JPasswordField();
+        PlainDocument document = (PlainDocument) test.getDocument();
+        document.setDocumentFilter(new DocumentFilter() {
+            @Override
+            public void replace(FilterBypass fb, int offset,
+                                int length, String text, AttributeSet attrs)
+                    throws BadLocationException
+            {
+                Document doc = fb.getDocument();
+                String string = doc.getText(0, doc.getLength()) + text;
+                if (string.length() <= 6 && string.matches("[0-9]+")) {
+                    super.replace(fb, offset, length, text, attrs);
+                }
+            }
+        });
+        test.setText("123456");
+        test.setText("");
+
+        char[] password = test.getPassword();
+        if (password.length != 0) {
+            throw new RuntimeException(Arrays.toString(password));
+        }
+    }
+}