FULL PRODUCT VERSION :
java version "1.6.0_04"
Java(TM) SE Runtime Environment (build 1.6.0_04-b12)
Java HotSpot(TM) Client VM (build 10.0-b19, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Any OS which exhibits Bug #4797189.

A DESCRIPTION OF THE PROBLEM :
Line 1228 of PNGImageReader creates a new Inflater and passes it into an InflaterInputStream:

            is = new InflaterInputStream(is, new Inflater());

Inspection of the InflaterInputStream code reveals that this Inflater will never be "end"ed, even by a call to "close", causing a leak of memory as described in Bug #4797189.

A reference to the Inflater should be maintained and properly "end"ed in the "PNGImageReader .dispose" method.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the attached program to reproduce.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected normal heap usage.
ACTUAL -
Actual heap usage mimics that of Bug #4797189.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.io.File;

import javax.imageio.ImageReadParam;
import javax.imageio.stream.FileImageInputStream;
import javax.imageio.stream.ImageInputStream;

import com.sun.imageio.plugins.png.PNGImageReader;
import com.sun.imageio.plugins.png.PNGImageReaderSpi;

public class Leak
{
    public static void main(String[] args) throws Exception
    {
        while (true)
        {
            ImageInputStream stream = new FileImageInputStream(new File("image.png"));
            PNGImageReader imageReader = new PNGImageReader(new PNGImageReaderSpi());
            imageReader.setInput(stream);
            imageReader.read(0, new ImageReadParam());
            imageReader.dispose();
            stream.close();
        }
    }
}

---------- END SOURCE ----------