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From: Robert Ramey (ramey_at_[hidden])
Date: 2019-11-22 00:36:10

On 11/21/19 3:06 PM, Nicolas Guillot via Boost wrote:
>>> Thanks a lot for your help. And if any clarification is needed, I'm
>>> available of course !
>> Please do the following:
>> a) double check closed issues on git on the serialization library. I
>> recently fixed a bug which might be related. It might be helpful to
>> look at this and see if it matches your case.
>> b) Open up a github issue with all the information you've included in
>> this post.
>> c) I'll take a look at it.
>> Robert Ramey
> Hi Robert and thanks for your answer.
> I didn't know boost serialization project was on git hub. I only looked for
> a similar bug fix at boost website. And no release note since boost 1.58,

I fix bugs as they are found. I make other small enhancements all the
time. I'm remiss in not updating the release notes.

> wahoo! no bug !
> Please can you advice me a little bit: I guess the issue related to my
> problem is the issue 154 (

That's a good possibility
> What do you advise: take the code from git, or only the bug fix? Is the
> code source from git compatible with last version of boost (1.71.0)?

I advise downloading the whole library - latest version and re-building
it from scratch. For reasons I don't want to into now - this is harder
than it should be. But it's the only way that you know that you have
the latest package.

I also recommend that you run the test suite on your local system(s).
This is an incredibly exhaustive series of tests which almost guarentees
that you have a bug free combination of compiler, linker, other
libraries etc.

This seems like it would be a lot of work - it is. But it's better than
playing whack-a-mole trying to understand problems via experimentation.
These days any bug still existing is very, very, very, obscure and
almost impossible to find. It's very hard even to make a useful test
case. And if you can reproduce it, it's almost impossible to fix. So I
recommend downloading the whole of boost 1.71 and building everything
from scratch.

> If you advice to take only the commit that fix this issue, which is it?

I don't advise this, but if you want to do it this way, you'll just have
to read the comments as I don't remember.

> Now it's 0:00 in my part of the world, but tomorrow for sure I'll do the
> test and keep you inform.

Instead, how about doing what I suggest and informing me if it doesn't work.

> Thanks for your help, and congratulation for this library.

You're welcome, I'm happy to be of service.

Robert Ramey
> On Thu, Nov 21, 2019 at 5:51 PM Nicolas Guillot <nicolas.guillot_at_[hidden]>
> wrote:
>> We use boost serialization in ours projects, both on linux (gcc) and
>> Windows.
>> We encounter a problem only on Windows (for "every" versions of Windows (7
>> and 10) and of MSVC: Visual 2010 and 2015, ie. MSVC++ 10.0 _MSC_VER == 1600
>> or MSVC++ 14.0 _MSC_VER == 1900).
>> *Here is the problem summarized*, but I need to give more details after:
>> When I serialize a class
>> - which have base class
>> - and have 2 vector of shared_ptr of ClassB, with the same contents,
>> and B inherits from the same base class
>> the serialization works, but the deserialization doesn't ("input stream
>> error").
>> The following image is here : (if
>> it's not displayed)
>> [image: enter image description here]
>> <>
>> Yes, it's very strange:
>> - if I remove the base class, it works.
>> - if I inline the serialization code (empty function) of the base
>> class, it works.
>> - if the 2 vectors don't have the same content, it works !!
>> -
>> if I register the ClassBase in the serialize method of ClassTest, it
>> works. I.e.:
>> // in ClassTest:template <class Archive>void serialize(Archive & ar, const unsigned int version) {
>> ar.template register_type<ClassBase>();
>> ...}
>> *Some details*
>> *When it works* on linux, and when it works on Windows with ClassBase
>> type registration in the archive, we have the same xml output.
>> It's worth noting that:
>> - boost_serialization is version 17 on Windows and 9 on linux (I
>> didn't tried to update boost on linux yet).
>> - On BaseClass xml tag, the tracking_level="1", so we have object_id.
>> *And when it doesn't work* (once again: the serialization of ClassTest is
>> OK, but cannot deserialized "input stream error"):
>> - The main difference is in the serialization of ClassTest: the
>> ClassBase part has no tracking_level.
>> - However it's not the only cause, because if the vectors are
>> differents (same 2 first items, and a third item in one vector),
>> tracking_level of ClassBase in ClassTest part is "0".
>> Last thing, if it can give you some clues: while we debugged our
>> application, we noticed that the deserialization framework tries to
>> deserialize a class into another.
>> It makes me think the serialization framework is confused about the classe
>> types identifications.
>> Could it be a matter of dll linking? Of global static shared storage ?
>> I've posted a visual studio solution here
>> <!Aoy4ax0S3ZS5gkxv1UIvRUd32oVO?e=ACVi4c>.
>> Thanks a lot for your help. And if any clarification is needed, I'm
>> available of course !
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