Re: [Boost-bugs] [Boost C++ Libraries] #4660: Error read binary archive, created by old boost version

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #4660: Error read binary archive, created by old boost version
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-09-20 09:33:59

#4660: Error read binary archive, created  by old boost version
---------------------------------------+------------------------------------
  Reporter:  serge-voropaev@…          |       Owner:  ramey        
      Type:  Bugs                      |      Status:  reopened     
 Milestone:  Boost 1.45.0              |   Component:  serialization
   Version:  Boost 1.45.0              |    Severity:  Problem      
Resolution:                            |    Keywords:               
---------------------------------------+------------------------------------

Comment (by markus.henschel@…):

 Compatibility ist still broken. We have binary archives from 1.34.1 that
 fail to load in 1.51 now. I stepped through the code and it seems like the
 class_id is 2 bytes in 1.34.1 but 1.51 tries to load it as 4 bytes. See
 basic_binary_iarchive.hpp:

 This is what the code looks like in 1.51

 {{{
 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
     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);
     }
 }
 }}}

 1.34.1 has library version 4 and had this code
 {{{
 void load_override(class_id_type & t, int){
     // upto 32K classes
     int_least16_t x;
     * this->This() >> x;
     t = class_id_type(x);
 }
 }}}

 So it seems to me that this is the problem. I checked the source code of
 releases from 1.34 to 1.40 (library version 6) and it looks like the class
 id has always been 16 bits. So this is was the code should look like:

 {{{
 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/4660#comment:47>
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