[Cuis-dev] ReferenceStream cannot read Dictionary object written with Squeak (was Re: ReferenceStream restoreFromFile: aFileEntry goes into infinite loop)

[Nicolas Cellier]

The corresponding updates are:

https://source.squeak.org/trunk/Kernel-nice.962.diff
https://source.squeak.org/trunk/Kernel-nice.963.diff
https://source.squeak.org/trunk/Kernel-eem.969.diff

huh, 3 successive commits to get it right, you can do better ;-)

Le mar. 23 sept. 2025 à 23:11, Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> a écrit :

> Hi Juan,
> I fail to see the bug in current Squeak trunk.
> I tried this
>
>     | int out file |
>     int := SmallInteger maxVal.
>     file *:=* FileStream fileNamed: 'Test-Int'.
>     file binary.
>     (DataStream on: file) nextPut: int.
>     file close.
>
>     file *:=* FileStream fileNamed: 'Test-Int'.
>     file binary.
>     out *:=* (DataStream on: file) next.
>     file close.
>
>     self assert: int = out
>
> The large SmallInteger is restored correctly.
> This is because we find this method timestamped from 2015:
>
> *SmallInteger>>objectForDataStream:* refStrm
>     *"In a 64-bit Spur VM, we may have to fake 32-bit SmallIntegers for
> compatibility."*
>
>     | large |
>     self > 16r3FFFFFFF ifTrue: [
>         large *:=* LargePositiveInteger new: self digitLength neg: false.
>         1 to: self digitLength do: [:i | large digitAt: i put: (self
> digitAt: i)].
>         ^large].
>     self < -16r40000000 ifTrue: [
>         large *:=* LargeNegativeInteger new: self digitLength neg: true.
>         1 to: self digitLength do: [:i | large digitAt: i put: (self
> digitAt: i)].
>         ^large].
>     ^ self
>
> Did I overlook something?
> I hope that Cuis and Squeak DataStream will remain consistent after your
> latest changes
>
> Nicolas
>
> Le lun. 22 sept. 2025 à 15:45, Juan Vuletich via Cuis-dev <
> cuis-dev at lists.cuis.st> a écrit :
>
>> Hi,
>> On 22/09/2025 10:10 AM, H. Hirzel via Cuis-dev wrote:
>>
>> I could identify the change set which causes the problem, it is from last
>> Wednesday
>>
>> CoreUpdates\
>> 7580-ReferenceStream-61BitSmallIntegers-fix-JuanVuletich-2025Sep17-08h16m-jmv.001.cs.st
>>
>> It introduces a new version of #readInteger and writeInteger: in the
>> class DataStream.
>> If I undo the change of this change set it works.
>>
>> --Hannes
>>
>>
>> As you saw in that changeset (file name, comments in code, commit
>> message), and as exemplified in the test added to BaseImageTests shortly
>> after, what that code does is not to cause a problem, but to fix a serious
>> bug that has been around for a long time and that is still present in
>> Squeak. Just try to serialize an object with a largish SmallInteger and see
>> what you get back.
>>
>> Anyway. I just pushed a better implementation that uses a different
>> format for 32bit SmallIntegers than from larger ones. This brings back
>> compatibility with the badly broken Squeak format, although it obviously
>> can't bring back the bits that Squeak discarded when saving the file, and
>> results will be wrong unless you're lucky enough to only use small
>> SmallIntegers.
>>
>>
>>
>>
>>
>>
>>
>>
>> On Mon, Sep 22, 2025 at 2:36 PM H. Hirzel <hannes.hirzel at gmail.com>
>> wrote:
>>
>>> I am currently identifying which change set causes the problem.
>>> So far Cuis update 7523 still works.
>>>
>>> This means if I produce a file ' aDictWithByteArraysFromSq.obj' in
>>> Squeak I can read it in Cuis 7523
>>>
>>> So the problem has been introduced in one of the last 60 updates.
>>>
>>>
>>> "Squeak"
>>>> dict := Dictionary new.
>>>> dict at: 1 put: #[1 2 3 4].
>>>> dict at: 2 put: #[5 6 7 8].
>>>> dict at: 3 put: #[10 20 30 40].
>>>>
>>>> fileStream := ReferenceStream fileNamed:
>>>> 'aDictWithByteArraysFromSq.obj'.
>>>> objectToSave := dict.
>>>> fileStream nextPut: objectToSave.
>>>> fileStream close
>>>>
>>>>
>>>
>>>> "-----------------------------------------------"
>>>> "Restore in Cuis"
>>>> ReferenceStream restoreFromFile: ('aDictWithByteArraysFromSq.obj'
>>>> asFileEntry).
>>>>
>>>> "Result
>>>> OK in Cuis 7523
>>>> NOT OK in Cuis 7584"
>>>>
>>>>
>> --
>> Juan Vuletichwww.cuis.stgithub.com/jvuletichresearchgate.net/profile/Juan-Vuletichindependent.academia.edu/JuanVuletichpatents.justia.com/inventor/juan-manuel-vuletich
>>
>> --
>> Cuis-dev mailing list
>> Cuis-dev at lists.cuis.st
>> https://lists.cuis.st/mailman/listinfo/cuis-dev
>>
>
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