IO-568: AutoCloseInputStream should disable mark/reset

src/main/java/org/apache/commons/io/input/AutoCloseInputStream.java

@@ -32,18 +32,36 @@
  * stream as soon as possible even if the client application (by not explicitly
  * closing the stream when no longer needed) or the underlying stream (by not
  * releasing resources once the last byte has been read) do not do that.
+ * <p>
+ * Since there is no safe way to always close the stream when reaching the end and
+ * respecting mark/reset contract, it's possible to force disabled mark support.
+ * This is highly recommended when you don't know how the stream is going to be used
+ * (mark is not disabled by default for retro compatibility reasons).
  *
  * @since 1.4
  */
 public class AutoCloseInputStream extends ProxyInputStream {
 
+    private boolean markEnabled = true;
+
     /**
      * Creates an automatically closing proxy for the given input stream.
      *
      * @param in underlying input stream
      */
     public AutoCloseInputStream(final InputStream in) {
+        this(in, true);
+    }
+
+    /**
+     * Creates an automatically closing proxy for the given input stream.
+     *
+     * @param in underlying input stream
+     */
+    public AutoCloseInputStream(final InputStream in, boolean markEnabled) {
         super(in);
+
+        this.markEnabled = markEnabled;
     }
 
     /**
@@ -79,6 +97,33 @@ protected void afterRead(final int n) throws IOException {
         }
     }
 
+    @Override
+    public synchronized void mark(int readlimit) {
+        if (this.markEnabled) {
+            super.mark(readlimit);
+        }
+    }
+
+    @Override
+    public synchronized void reset() throws IOException {
+        if (this.markEnabled) {
+            super.reset();
+        } else {
+            // Behave as standard InputStream not supporting mark/reset
+            throw new IOException("mark/reset not supported");
+        }
+    }
+
+    @Override
+    public boolean markSupported() {
+        if (this.markEnabled) {
+            return super.markSupported();
+        } else {
+            // Behave as standard InputStream not supporting mark/reset
+            return false;
+        }
+    }
+
     /**
      * Ensures that the stream is closed before it gets garbage-collected.
      * As mentioned in {@link #close()}, this is a no-op if the stream has

src/test/java/org/apache/commons/io/input/MarkEnabledAutoCloseInputStreamTest.java

@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.io.input;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * JUnit Test Case for {@link AutoCloseInputStream} with enabled mark support (the default).
+ */
+public class MarkEnabledAutoCloseInputStreamTest extends AbstractAutoCloseInputStreamTest {
+
+    public MarkEnabledAutoCloseInputStreamTest() {
+        super(true);
+    }
+
+    @Test
+    public void testMark() throws IOException {
+        assertTrue(targetStream.markSupported());
+
+        // Make sure mark is disabled
+        assertTrue(stream.markSupported());
+
+        // Check that mark() does not fail
+        stream.mark(1);
+        assertTrue("not marked", marked);
+
+        assertEquals('x', this.stream.read());
+
+        // Check that reset() works
+        stream.reset();
+        assertTrue("not reseted", reseted);
+
+        assertEquals('x', this.stream.read());
+    }
+}