If an IndexColorModel is created with some transparent black entries (i.e. 0x0)
but no transparent pixel is specified, then the getDataElements does not
return that pixel value when given a transparent black rgb value.

-- Begin TransparentLookupTest.java --

import java.awt.image.IndexColorModel;
import java.awt.image.DataBuffer;

public class TransparentLookupTest {
    public static void main(String argv[]) {
	// Create a 6x6x6 color cube
	int[] cmap = new int[256];
	int i=0;
	for (int r=0; r < 256; r += 51) {
	    for (int g=0; g < 256; g += 51) {
		for (int b=0; b < 256; b += 51) {
		    cmap[i++] = (r<<16)|(g<<8)|b;
		}
	    }
	}

	testFindTP(new IndexColorModel(8, 256, cmap, 0, true, -1,
				       DataBuffer.TYPE_BYTE));
    }

    public static void testFindTP(IndexColorModel icm) {
	byte pix[] = (byte[]) icm.getDataElements(0, null);
	int rgb = icm.getRGB(pix[0] & 0xff);
	if (rgb != 0) {
	    throw new RuntimeException("Transparent black (0x00) resolves to ("+
				       Integer.toHexString(rgb)+")");
	}
    }
}