[squeak-dev] PNGReadWriter buglet

tim Rowledge tim at rowledge.org
Sun Feb 26 22:57:48 UTC 2023


Nice detective work.

I just sat down to take a look at this again... and the power goes off so I have to shut everything down. Oh joy.

> On 2023-02-26, at 2:52 PM, David T. Lewis <lewis at mail.msen.com> wrote:
> 
> Narrowing it down some more:
> 
> By replaying the update stream in a Squeak 4.5 image, I can see that
> the problem is introduced in update-eem.279, and that the package change 
> that introduced it is Compression-eem.41.
> 
> However, the package has only two method changes, and reverting these 
> methods in a Squeak trunk image does not make the the problem go away, 
> so maybe there are some other related changes later in the update stream.
> 
> I don't understand the actual problem, but maybe this will help narrow 
> it down.
> 
> Dave
> 
> sun, Feb 26, 2023 at 02:52:12PM -0500, David T. Lewis wrote:
>> Confirming on 64 bit Intel linux with the zipped file.
>> 
>> I see the bug on Squeak 6 with opensmalltalk-vm and the same with
>> an up to date interpreter VM on trunk level V3 image.
>> 
>> With the same interpreter VM, I do not see the bug on Squeak 3.6,
>> 3.8, 3.9, or 4.5. But with Squeak 4.6 the bug is present.
>> 
>> I get the same results with a Cog VM comparing 4.5 to 4.6.
>> 
>> So it looks like something in the image (not VM or plugins), and
>> it seems to have appeared some time between the Squeak 4.5 and
>> Squeak 4.6 releases.
>> 
>> Dave
>> 
>> On Sun, Feb 26, 2023 at 08:14:06PM +0100, karl ramberg wrote:
>>> I see the bug now.
>>> The PNG is rasterized as you showed in the first email.
>>> 
>>> Best,
>>> Karl
>>> 
>>> On Sun, Feb 26, 2023 at 8:02???PM tim Rowledge <tim at rowledge.org> wrote:
>>> 
>>>> 
>>>> 
>>>>> On 2023-02-26, at 10:43 AM, Vanessa Freudenberg <vanessa at codefrau.net>
>>>> wrote:
>>>>> 
>>>>> No issue on Mac ARM either, looks good.
>>>>> 
>>>>> Maybe send it inside a zip.
>>>> 
>>>> Good idea
>>>> 
>>>> 
>>>> 
>>>>> Vanessa
>>>>> 
>>>>> On Sun, Feb 26, 2023 at 10:37 AM karl ramberg <karlramberg at gmail.com>
>>>> wrote:
>>>>> Hi,
>>>>> Not sure if it's been altered.
>>>>> Can you send the image again as attachment, so the browser doesn't
>>>> interfere in the middle?
>>>>> 
>>>>> Best,
>>>>> Karl
>>>>> 
>>>>> On Sun, Feb 26, 2023 at 7:25???PM tim Rowledge <tim at rowledge.org> wrote:
>>>>> 
>>>>> 
>>>>>> On 2023-02-25, at 10:53 PM, karl ramberg <karlramberg at gmail.com>
>>>> wrote:
>>>>>> 
>>>>>> I don't see any problems with this PNG on Windows in an updated trunk
>>>> image.
>>>>> 
>>>>> OK, that really confuses me.
>>>>> 
>>>>> It looks identical on
>>>>> - raspberry pi 5.3 32bit
>>>>> - raspberry pi 5.3 64bit
>>>>> - raspberry pi 6 trunk 64 bit
>>>>> - iMac intel 6 trunk 64 bit
>>>>> - iMac intel 5.3 64bit
>>>>> - intel ubuntu 6 trunk 64bit
>>>>> - intel ubuntu 5.3 64bit
>>>>> 
>>>>> What could make it work on Windows? 64 or 32bit? Windows version?
>>>>> 
>>>>> Is there any chance the file got altered before you loaded it in Squeak?
>>>>> 
>>>>> 
>>>>> tim
>>>>> --
>>>>> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>>>>> Strange OpCodes: RBR: Remove Bits Randomly
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> tim
>>>> --
>>>> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>>>> Useful Latin Phrases:- Tam exanimis quam tunica nehru fio. = I am as dead
>>>> as the nehru jacket.
>>>> 
>>>> 
>>>> 
>>>> 
>> 
>>> 
>> 
>> 
> 
> 


tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Strange OpCodes: CAO: Compare Apples to Oranges




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