[OpenJDK 2D-Dev]  RFR [JDK-6686236] GIF native IIOMetadata assumes characterCellWidth/Height as 2bytes
Prahalad Kumar Narayanan
prahalad.kumar.narayanan at oracle.com
Fri Mar 16 12:01:04 UTC 2018
Good day to you.
Request your time in reviewing a simple fix for
. Bug : [JDK-6686236] https://bugs.openjdk.java.net/browse/JDK-6686236
. Title : GIF native IIOMetadata assumes characterCellWidth/Height as 2bytes
. As per the gif image format specification (v89a), Character Cell Width and Character Cell Height values in Plain Text Extension block occupy 1 Byte each.
. However, the GIFImageMetadataFormat and GIFWritableImageMetadata allow values in range [1, 65535] for the above attributes.
. Note: Luckily, The bug does not affect GIFImageWriter because it writes only a single byte to the output stream. Thus ignoring the 3 higher order bytes in the "int" variables used for the two attributes.
Information on Fix:
. The max permissible value is now restricted to 255 in both GIFImageMetadataFormat and GIFWritableImageMetadata.
. In addition, the html documentation describing GIF Image Metadata has been modified.
. The attached test case verifies changes taken up in both metadata and metadata format.
Kindly review the change at your convenience.
Thank you for your time
Have a good day
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