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

[Phil Race]

Would it not be better to be explicit in this so as not to leave it to 
chance ?

-phil.

On 11/05/2015 11:49 PM, prasanta sadhukhan wrote:
> 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
>>>>>
>>>>
>>>
>