Re: [Boost-bugs] [Boost C++ Libraries] #5499: Serialization backward compatability

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #5499: Serialization backward compatability
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-01-26 10:59:51

#5499: Serialization backward compatability
-------------------------------------+--------------------------------------
  Reporter:  ybungalobill@…          |       Owner:  ramey                      
      Type:  Bugs                    |      Status:  new                        
 Milestone:  To Be Determined        |   Component:  serialization              
   Version:  Boost 1.46.1            |    Severity:  Showstopper                
Resolution:                          |    Keywords:  serialization compatability
-------------------------------------+--------------------------------------

Comment (by s.skorniakov@…):

 Same problem while upgrading from 1.36.0 to 1.48.0.
 I had checked basic_binary_iarchive::load_override for class_id_type -
 from versions 1.32.0 to 1.43.0 (serialization library versions from 3 to
 7) its identical:
 {{{
     void load_override(class_id_type & t, int){
         // upto 32K classes
         int_least16_t x;
         * this->This() >> x;
         t = class_id_type(x);
     }
 }}}
 In version 1.44.0 (library version 8) load_override for class_id_type is
 not specialized in basic_binary_iarchive.
 In version 1.48.0 I see
 {{{
         library_version_type lvt = this->get_library_version();
         if(boost::archive::library_version_type(7) < lvt){
             this->detail_common_iarchive::load_override(t, version);
         }
         else
         if(boost::archive::library_version_type(6) < lvt){
             int_least16_t x=0;
             * this->This() >> x;
             t = boost::archive::class_id_type(x);
         }
         else{
             int x=0;
             * this->This() >> x;
             t = boost::archive::class_id_type(x);
         }
 }}}
 I do not understand, why author made difference between version 7 and
 earlier versions. From my point of view, it is an error (introduced in
 version 1.45.0). Following code can read my old files (library versions
 3-5) :
 {{{
     void load_override(class_id_type & t, int version){
         library_version_type lvt = this->get_library_version();
         if(boost::archive::library_version_type(7) < lvt){
             this->detail_common_iarchive::load_override(t, version);
         }
         else
         {
             int_least16_t x=0;
             * this->This() >> x;
             t = boost::archive::class_id_type(x);
         }
     }
  }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5499#comment:1>
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