On Mon, 3 Oct 2022 06:41:03 GMT, Jayathirth D V <[email protected]> wrote:
>> src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageWriter.java
>> line 1463:
>>
>>> 1461: return false;
>>> 1462: }
>>> 1463: if (compressionType == BI_RLE4 && bpp != 4) {
>>
>> I'm confused. You say you are relaxing the test to allow 15bpp, but I don't
>> see where you're removing
>> anything that would have rejected 15bpp.
>>
>> And how does this prevent the un-specified exception being thrown ?
>
> Hi Phil,
>
> We never had any bpp check to verify what standard bpp's should be allowed in
> BMP.
> Because of this when we tried to decode 2 bpp PNG img and write it to BMP we
> used to get IOOBE as captured in https://bugs.openjdk.org/browse/JDK-8262297.
> So under this bug, check was added to allow only standard bpp's for BMP
> encoding :
> https://github.com/openjdk/jdk/commit/c73319354399596ab2b9aab0a7f62e8fa0ab9365.
>
>
> But this caused regression of many jtreg tests which were using
> USHORT_555_RGB to encode BMP image(we round off this 15bpp to 16bpp and at
> later stage :
> https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageWriter.java#L472
> and store it in 16bit data buffer). So i relaxed this check which caused
> jtreg regressions to allow 15bpp also.
>
> Since we straight away reject non-standard bits per pixel (like 2 bpp) for
> BMP encoding, we will throw IOException instead to going ahead and throwing
> non-documented exceptions like IOOBE.
Ah, the bit you weren't / aren't explaining is that the reason I'm not seeing
the check which would have dis-allowed 15bpp
is that you backed it out ages ago
https://github.com/openjdk/jdk/commit/84aa0a191b085a3d7cb338fd5e67281d0e4b57be
because of the failures it caused.
So now that code is being re-added but this time allowing 15bpp
-------------
PR: https://git.openjdk.org/jdk/pull/10419
