Name: auR10023 Date: 05/22/2003



Method java.util.zip.InflaterInputStream.available() returns 0 but 1
expected. The javadoc for this method says:

...
public int available()
              throws IOException

          Returns 0 after EOF has been reached, otherwise always return 1.

          Programs should not count on this method to return the actual number of bytes that could be read without blocking.
          ...

Following test skips valid amount of bytes, so there should be no EOF.


Here is the example:

-------t.java---------
import java.util.zip.*;
import java.io.*;

public class t {
    private final static byte orig[] = {
        125, 28, 58, 101, 36, 5, 64, 55, 77, 68, 42,
        71, 84, 125, 15, 74, 104, 44, 49, 28, 22, 17,
        19, 68, 121, 123, 100, 75, 76, 120, 30, 54,
        64, 21, 36, 35, 54, 82, 65, 118, 82, 1, 68,
        19, 3, 72, 99, 72, 36, 61, 3, 87, 115, 104,
        21, 71, 77, 120, 21, 84, 110, 38, 39, 2, 14,
        91, 43, 127, 28, 91, 112, 73, 20, 30, 120,
        72, 43, 55, 102, 105, 57, 64, 58, 61, 96,
        126, 122, 52, 66, 111, 83, 57, 9, 45, 5, 47,
        117, 35, 51, 60
    };
    private final static byte compressedOrig[] = {
        120, -100, -85, -107, -79, 74, 85, 97, 117,
        48, -9, 117, -47, 114, 15, -87, -27, -9, -54,
        -48, 49, -108, 17, 19, 20, 118, -87, -84, 78,
        -15, -10, -87, -112, 51, 115, 16, 85, 81, 54,
        11, 114, 44, 11, 98, 116, 17, 102, -10, 72,
        -10, 80, -79, 101, 14, 47, -50, 16, 117, -9,
        -83, 16, 13, -55, 83, 83, 103, -30, -117, -42,
        -82, -105, -119, 46, -16, 20, -111, -85, -16,
        -48, 54, 79, -53, -76, 116, -80, -78, 77, -88,
        -85, 50, 113, -54, 15, -74, -28, -44, 101,
        -43, 47, 85, 54, -74, 1, 0, -34, -35, 25, 7
    };

    public static void main(String [] args) {
        boolean passed = false;
        byte[] buf = new byte[orig.length];
        InputStream bis = new ByteArrayInputStream(compressedOrig);
        InflaterInputStream iis = new InflaterInputStream(bis);
        try {
            iis.skip(orig.length);
            if (iis.available() == 1) {
                passed = true;
            }
            iis.close();
        } catch (IOException e) {
            passed = false;
            System.out.println("Unexpected " + e + " thrown.");
        }
        System.out.println( passed);
    }
}


Here is the result
#java -version
java version "1.5.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta-b06)
Java HotSpot(TM) Client VM (build 1.5.0-beta-b06, mixed mode)

#java t
false

Following jck test fail due to this bug:

api/java_util/zip/InflaterInputStream/index.html#Misc[InflaterInputStream0005]

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