bug 61294 -- prevent infinite loop in IOUtils' skipFully.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1801844 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 136 insertions, 0 deletions

diff --git a/src/testcases/org/apache/poi/util/TestIOUtils.java b/src/testcases/org/apache/poi/util/TestIOUtils.java
new file mode 100644
index 0000000000..8026820e79
--- /dev/null
+++ b/src/testcases/org/apache/poi/util/TestIOUtils.java
@@ -0,0 +1,136 @@
+/* ====================================================================
+   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.poi.util;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Random;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/**
+ * Class to test IOUtils
+ */
+public final class TestIOUtils {
+    static File TMP = null;
+    static long SEED = new Random().nextLong();
+    static Random RANDOM = new Random(SEED);
+
+    @BeforeClass
+    public static void setUp() throws IOException {
+        TMP = File.createTempFile("poi-ioutils-", "");
+        OutputStream os = new FileOutputStream(TMP);
+        for (int i = 0; i < RANDOM.nextInt(10000); i++) {
+            os.write(RANDOM.nextInt((byte)127));
+        }
+        os.flush();
+        os.close();
+
+    }
+
+    @AfterClass
+    public static void tearDown() throws IOException {
+        TMP.delete();
+    }
+
+    @Test
+    public void testSkipFully() throws IOException {
+        InputStream is =  new FileInputStream(TMP);
+        long skipped = IOUtils.skipFully(is, 20000L);
+        assertEquals("seed: "+SEED, -1L, skipped);
+    }
+
+    @Test
+    public void testSkipFullyGtIntMax() throws IOException {
+        InputStream is =  new FileInputStream(TMP);
+        long skipped = IOUtils.skipFully(is, Integer.MAX_VALUE + 20000L);
+        assertEquals("seed: "+SEED, -1L, skipped);
+    }
+
+    @Test
+    public void testSkipFullyByteArray() throws IOException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        InputStream is = new FileInputStream(TMP);
+        IOUtils.copy(is, bos);
+        long skipped = IOUtils.skipFully(new ByteArrayInputStream(bos.toByteArray()), 20000L);
+        assertEquals("seed: "+SEED, -1L, skipped);
+    }
+
+    @Test
+    public void testSkipFullyByteArrayGtIntMax() throws IOException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        InputStream is = new FileInputStream(TMP);
+        IOUtils.copy(is, bos);
+        long skipped = IOUtils.skipFully(new ByteArrayInputStream(bos.toByteArray()), Integer.MAX_VALUE+ 20000L);
+        assertEquals("seed: "+SEED, -1L, skipped);
+    }
+
+    @Test
+    public void testWonkyInputStream() throws IOException {
+        long skipped = IOUtils.skipFully(new WonkyInputStream(), 10000);
+        assertEquals("seed: "+SEED, 10000, skipped);
+    }
+
+    /**
+     * This returns 0 for the first call to skip and then reads
+     * as requested.  This tests that the fallback to read() works.
+     */
+    private static class WonkyInputStream extends InputStream {
+        int skipCalled = 0;
+        int readCalled = 0;
+
+        @Override
+        public int read() throws IOException {
+            readCalled++;
+            return 0;
+        }
+
+        @Override
+        public int read(byte[] arr, int offset, int len) throws IOException {
+            readCalled++;
+            return len;
+        }
+
+        @Override
+        public long skip(long len) throws IOException {
+            skipCalled++;
+            if (skipCalled == 1) {
+                return 0;
+            } else if (skipCalled > 100) {
+                return len;
+            } else {
+                return 100;
+            }
+        }
+
+        @Override
+        public int available() {
+            return 100000;
+        }
+    }
+}