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

[Sergey Bylokhov]

Thanks for clarification. The fix looks fine then.

On 07.12.15 18:43, prasanta sadhukhan wrote:
> Hi Sergey,
>
> clearCache(index) is called from 2 places one from setGlyphPositions()
> which I fixed and other one from setGlyphTransform() and
> setGlyphTransform is called from public setGlyphTransform() which
> already have a check for IOB
> if (ix < 0 || ix >= glyphs.length) {
>              throw new IndexOutOfBoundsException("ix = " + ix);
>          }
> so this (setGlyphPositions) is the only place where it was called wrongly.
>
> Regards
> Prasanta
> On 12/7/2015 9:01 PM, Sergey Bylokhov wrote:
>> 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.