[OpenJDK 2D-Dev] [9] RFR JDK-7160052: GlyphVector.setGlyphPosition can throw an exception on valid input

[Sergey Bylokhov]

Hi, Prasanta.
Can you please confirm that we properly use clearCaches() in other 
places of StandardGlyphVector.java?

On 27.11.15 14:48, prasanta sadhukhan wrote:
> Hi All,
>
> Please review a fix for jdk9
> Bug: https://bugs.openjdk.java.net/browse/JDK-7160052
> webrev: http://cr.openjdk.java.net/~psadhukhan/7160052/webrev.00/
>
> Issue:
> GlyphVector.setGlyphPosition(int glyphIndex, Point2D
> <imap://Sergey%2EBylokhov%40oracle%2Ecom@stbeehive.oracle.com:993/fetch%3EUID%3E/mailing%20list/2d%3E5454?header=quotebody&part=1.2.2&filename=Point2D.html> newPos)
> can have glyphIndex "equal" to the number of glyphs in this GlyphVector
> so if user tries to call GlyphVector.setGlyphPosition(gv.getNumGlyphs(),
> gv.getGlyphPosition(gv.getNumGlyphs()) it throws IndexOutOfBoundsException
>
> Cause:
> StandardGlyphVector maintains a glyph cache for the glyphs stored in the
> GlyphVector via lbcache = new Shape[glyphs.length];
>
> When GlyphVector.setGlyphPosition() is called, it positions the glyph at
> the specified glyphIndex|||||||||| and tries to clear the mentioned
> glyphIndex position of cache by calling clearCache(glyphIndex)
> But, if we pass the glyphIndex == number of glyphs, then it tries to
> access beyond the cache array resulting in IOB.
>
> Fix:
> Checked if glyphIndex passed as argument is equal to number of glyphs
> then do not try to clear the cache as setGlyphPosition() will anyway
> sets the position after the last glyph.
> Also, added this check as per spec|IndexOutOfBoundsException
> <imap://Sergey%2EBylokhov%40oracle%2Ecom@stbeehive.oracle.com:993/fetch%3EUID%3E/mailing%20list/2d%3E5454?header=quotebody&part=1.2.3&filename=IndexOutOfBoundsException.html>|
> - if |glyphIndex| is less than 0 or greater than the number of glyphs in
> this |GlyphVector
> |
> Regards
> Prasanta
>
> ||||


-- 
Best regards, Sergey.