Add test testForceDeleteReadOnlyFile.

Author: garydgregory

src/test/java/org/apache/commons/io/FileUtilsTestCase.java

@@ -1464,6 +1464,24 @@ public void testForceDeleteDir() throws Exception {
         assertFalse(testDirectory.exists(), "TestDirectory must not exist");
     }
 
+    @Test
+    public void testForceDeleteReadOnlyFile() throws Exception {
+        File destination = File.createTempFile("test-", ".txt");
+        assertTrue(destination.setReadOnly());
+        assertTrue(destination.canRead());
+        assertFalse(destination.canWrite());
+        // sanity check
+        assertTrue(destination.delete());
+        destination = File.createTempFile("test-", ".txt");
+        // real test
+        assertTrue(destination.setReadOnly());
+        assertTrue(destination.canRead());
+        assertFalse(destination.canWrite());
+        assertTrue(destination.exists(), "File doesn't exist to delete");
+        FileUtils.forceDelete(destination);
+        assertTrue(!destination.exists(), "Check deletion");
+    }
+
     @Test
     public void testForceMkdir() throws Exception {
         // Tests with existing directory