[Boost-bugs] [Boost C++ Libraries] #2010: bas64 iterator improvement

Subject: [Boost-bugs] [Boost C++ Libraries] #2010: bas64 iterator improvement
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-06-14 16:07:39

#2010: bas64 iterator improvement
----------------------------------+-----------------------------------------
 Reporter:  ramey                 |       Owner:  ramey  
     Type:  Tasks                 |      Status:  new    
Milestone:  Boost 1.36.0          |   Component:  None   
  Version:  Boost 1.35.0          |    Severity:  Problem
 Keywords:  serialization base64  |  
----------------------------------+-----------------------------------------
 {{{
  Hello,
 >
 > Code that pads base64 output with '=' looks in
 > basic_text_oprimitive.ipp like following:
 >
 >    std::size_t padding = 2 - count % 3;
 >    if(padding > 1)
 >        *oi = '=';
 >        if(padding > 2)
 >            *oi = '=';
 >
 > It will give the following transformations of a few simple strings:
 >
 > "012" -> "MDEy="
 > "0123" -> "MDEyMw"
 > "01234" -> "MDEyMzQ"
 > "012345" -> "MDEyMzQ1="
 >
 > Which violates the principle of the base 64 that the encoded output
 > length is multiple of 4 bytes. Right output for the samples above
 > should be:
 >
 > "012" -> "MDEy"
 > "0123" -> "MDEyMw=="
 > "01234" -> "MDEyMzQ="
 > "012345" -> "MDEyMzQ1"
 >
 >
 > The problem with the code above is that the condition (padding > 2)
 > is never satisfied. I think that the proper code should look like
 >
 >        std::size_t padding = 2 - count % 3;
 >        if (padding < 2) {
 >          *oi = '=';
 >          if (padding > 0)
 >            *oi = '=';
 >        }



 }}}

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/2010>
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