On Mon, 8 May 2023 18:44:00 GMT, Sergey Bylokhov <[email protected]> wrote:
>> I do not know why `WritableRaster.setRect(Raster)` computes intersection
>> with its own code in the method body instead of delegating to
>> `Rectangle.intersection(Rectangle)` in the same way as
>> `BufferedImage.setData(Raster)` does. For now I see no technical reason. I'm
>> tempted to add a commit to this pull request for replacing the intersection
>> calculation of `WritableRaster.setRect(Raster)`, but abstained for now
>> because I though that reviewers or sponsors may want to minimize the
>> changes. However I believe that this replacement would be desirable at least
>> for the extra robustness of `Rectangle` regarding underflow and overflow.
>
> Can we prove the overflow issue there by some test? If yes then probably it
> would be useful to fix it as well, probably even as separate bug which can be
> later backported.
In theory the following code would demonstrate the overflow:
var sm = new BandedSampleModel(DataBuffer.TYPE_BYTE, 100, 100, 1);
var r1 = Raster.createWritableRaster(sm, new Point(Integer.MAX_VALUE - 150, 0));
var r2 = Raster.createWritableRaster(sm, new Point(Integer.MAX_VALUE - 50,
0)); // Overflow on X.
r1.setRect(r2);
It practice it does not happen so easily because the `Raster` constructor
detects in advance the overflow and throws a `RasterFormatException` saying
_"overflow condition for X coordinates of Raster"_. However because the
`Raster.minX` field is protected and non-final, the constructor check can be
bypassed as below:
var r2 = new WritableRaster(sm, new Point()) {
{ // Constructor
minX = Integer.MAX_VALUE - 50;
sampleModelTranslateX = minX;
}
};
In which case the overflow happens and manifest itself with an
`ArrayIndexOutOfBoundsException`. I do not know if this is considered a too
convolved case for being worth a fix. However using the `BufferedImage` code,
in addition of being robust to this case, would also be simpler.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/13797#discussion_r1192681645
