[OpenJDK 2D-Dev] [9]: RFR JDK-8023213 [macosx] closed/java/awt/FontClass/NaNTransform.java fails on MacOS X 10.9

[prasanta sadhukhan]

Hi Phil,

On 11/5/2015 4:54 AM, Philip Race wrote:
> This does not look right to me. Who knows what data is on the canvas ?
> it is not clear that it is 'blank'. It could have data from a previous 
> glyph .. I am not
> sure how you know for sure. I can see that canvas is re-used. There is 
> reference
> to a "global shared canvas".
> And the actual function you invoke is one of two : one for grey and 
> one for lcd and
> looking at the grey one CGGI_CopyImageFromCanvasToAlphaInfo)
> it utilises info->width and info->height which can't be NaN because they
> are uint16 but I don't know if they are valid .. and is the "image" field
> allocated to be 0 length ? 
info->width & height is coming out to be 0 in case of NaN transform 
therefore "image" field will be of 0 length so "empty" glyph will be 
copied when we copy the "glyph image" from canvas (no matter what is 
there in canvas) to info->image via this code
http://hg.openjdk.java.net/jdk9/client/jdk/file/298d3fe64572/src/java.desktop/macosx/native/libawt_lwawt/font/CGGlyphImages.m#l294


size_t destRow = y * destRowWidth;
size_t srcRow = y * srcRowWidth;
size_t x;
for (x = 0; x < destRowWidth; x++) {
UInt32 p = src[srcRow + x];
dest[destRow + x] = CGGI_ConvertBWPixelToByteGray(p);

where destRowWidth = destRow = info->width will be 0 so dest = 
info->image will be of 0 length

Regards
Prasanta
> Could you step through how this is all guaranteed
> to be safe/correct ?
>
> -phil.
>
> On 11/2/15, 12:41 AM, prasanta sadhukhan wrote:
>> Hi Phil,
>>
>> I have modified as per your review to populate GlyphInfo with "empty" 
>> glyph
>> and also moved your existing test to "open"
>> I also added a Infinite Transform test along with your NaN transform 
>> just incase (in fact Sergey informally asked me to check)
>>
>> http://cr.openjdk.java.net/~psadhukhan/8023213/webrev.01/
>>
>> Regards
>> Prasanta
>> On 10/30/2015 1:03 AM, Phil Race wrote:
>>> Should this new check go before this :
>>>
>>> CGGI_ClearCanvas(canvas, info);
>>>
>>> since it is using info which is where you get NaN from.
>>>
>>>
>>> And should we then populate the returned canvas and info to
>>> ensure that we return an "empty" glyph rather than garbage values ?
>>> It is not clear to me that this is occurring.
>>>
>>> Why does the bug report not contain the evaluation below ?
>>> Also why is there a new test ? I would expect SQE would
>>> want to run the existing test to verify this fix.
>>> Should we not just open the existing test ?
>>>
>>>
>>> -phil.
>>>
>>> On 10/13/2015 04:49 AM, prasanta sadhukhan wrote:
>>>> Gentle reminder for review
>>>>
>>>> Regards
>>>> Prasanta
>>>> On 10/6/2015 3:25 PM, prasanta sadhukhan wrote:
>>>>> Hello All,
>>>>>
>>>>> Please review a fix for jdk9
>>>>>
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8023213
>>>>> webrev: http://cr.openjdk.java.net/~psadhukhan/8023213/webrev.00/
>>>>>
>>>>> drawString takes long time in mac native call 
>>>>> CGContextShowGlyphsAtPoint() if NaN transform is used which 
>>>>> translated to x & y being NaN.
>>>>> Fix is to prevent calling mac api for such invalid usage.
>>>>>
>>>>> Regards
>>>>> Prasanta
>>>>
>>>
>>