[OpenJDK 2D-Dev] [9] RFR: [JDK-6852563] ArrayOutOfBoundException when reading RLE8 compressed bitmap

[Prahalad Kumar Narayanan]

Hello Everyone

Good day to you.

Request your time in reviewing the fix for the bug
[JDK-6852563] ArrayOutOfBoundException when reading RLE8 compressed bitmap

Root Cause
    . The issue is similar to JDK-8167278 except for the difference in the Bitmap's compression format.
    . The issue surfaces when either of the following holds true-
            . When a malformed RLE8 bitmap image is decoded /or
            . When a valid RLE8 bitmap image with 'Delta sequence' is decoded.    

Details on the Fix:
    . Necessary guard conditions have been put in RLE8 bitmap decoding code.
    . Handling of Delta encoding (0x00 0x02 xOffset yOffset) in source image has been corrected with appropriate logic.
    . [Note] No regression test case has been provided with the fix. 
            . The fix will require input RLE8 bitmap as mentioned in the root cause.
            . When we tried to create one such bitmap using Gimp editor, the resulting image didn't contain corruption /or the delta sequence to trigger the issue.
            . However, the fix was tested with all RLE8 Bitmap images from bitmap test suite (including corrupt images) and no issues were seen.

Other Details:
    . The fix was run through both Jtreg and JCK test suites. No regressions were noticed.

The changes are available for your review under: 
    Link: http://cr.openjdk.java.net/~pnarayanan/6852563/webrev.00/

Kindly review the changes at your convenience and share your feedback.

Thank you for your time in review
Have a good day

Prahalad N.