Fix bug where count inaccurate after End of File

bug 33336, from Marcelo Liberato

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/io/trunk@154514 13f79535-47bb-0310-9956-ffa450edef68

Author: Stephen Colebourne

project.xml

@@ -158,6 +158,9 @@
     <contributor>
       <name>Jason Anderson</name>
     </contributor>
+    <contributor>
+      <name>Marcelo Liberato</name>
+    </contributor>
     <contributor>
       <name>Alban Peignier</name>
       <email>alban.peignier at free.fr</email>

src/java/org/apache/commons/io/input/CountingInputStream.java

@@ -23,6 +23,7 @@
  * have passed through so far.
  *
  * @author Henri Yandell
+ * @author Marcelo Liberato
  * @version $Id$
  */
 public class CountingInputStream extends ProxyInputStream {
@@ -45,7 +46,7 @@ public CountingInputStream(InputStream in) {
      */
     public int read(byte[] b) throws IOException {
         int found = super.read(b);
-        this.count += found;
+        this.count += (found >= 0) ? found : 0;
         return found;
     }
 
@@ -56,18 +57,19 @@ public int read(byte[] b) throws IOException {
      */
     public int read(byte[] b, int off, int len) throws IOException {
         int found = super.read(b, off, len);
-        this.count += found;
+        this.count += (found >= 0) ? found : 0;
         return found;
     }
 
     /**
-     * Increases the count by 1. 
+     * Increases the count by 1 if a byte is successfully read. 
      *
      * @see java.io.InputStream#read()
      */
     public int read() throws IOException {
-        this.count++;
-        return super.read();
+        int found = super.read();
+        this.count += (found >= 0) ? 1 : 0;
+        return found;
     }
 
     /**

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003,2004 The Apache Software Foundation.
+ * Copyright 2003-2005 The Apache Software Foundation.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,10 @@
 /**
  * Tests the CountingInputStream.
  *
- * @author <a href="mailto:bayard@apache.org">Henri Yandell</a>
+ * @author Henri Yandell
+ * @author Marcelo Liberato
+ * @author Stephen Colebourne
+ * @version $Id$
  */
 public class CountingInputStreamTest extends TestCase {
 
@@ -78,5 +81,73 @@ public void testResetting() throws Exception {
         found = cis.read(result, 6, 5);
         assertEquals( found, cis.getCount() );
     }
-}
+    
+    public void testZeroLength1() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[0]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        int found = cis.read();
+        assertEquals(-1, found);
+        assertEquals(0, cis.getCount());
+    }
+
+    public void testZeroLength2() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[0]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        byte[] result = new byte[10];
+
+        int found = cis.read(result);
+        assertEquals(-1, found);
+        assertEquals(0, cis.getCount());
+    }
+
+    public void testZeroLength3() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[0]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        byte[] result = new byte[10];
 
+        int found = cis.read(result, 0, 5);
+        assertEquals(-1, found);
+        assertEquals(0, cis.getCount());
+    }
+
+    public void testEOF1() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[2]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        int found = cis.read();
+        assertEquals(0, found);
+        assertEquals(1, cis.getCount());
+        found = cis.read();
+        assertEquals(0, found);
+        assertEquals(2, cis.getCount());
+        found = cis.read();
+        assertEquals(-1, found);
+        assertEquals(2, cis.getCount());
+    }
+
+    public void testEOF2() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[2]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        byte[] result = new byte[10];
+
+        int found = cis.read(result);
+        assertEquals(2, found);
+        assertEquals(2, cis.getCount());
+    }
+
+    public void testEOF3() throws Exception {
+        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[2]);
+        CountingInputStream cis = new CountingInputStream(bais);
+
+        byte[] result = new byte[10];
+
+        int found = cis.read(result, 0, 5);
+        assertEquals(2, found);
+        assertEquals(2, cis.getCount());
+    }
+
+}