Bug in indirect_streambuf::seek_impl

[lodos@…]

Currently indirect_streambuf::seek_impl always modifies input and output pointers with code:

setg(0, 0, 0); setp(0, 0);

See detail/indirect_streambuf.hpp. However, this is incorrect for dual seekable streams buffers which only modifies one set of pointers on each seek (in or out). As a consequence, dual seekable devices cannot be correctly seek. Those 2 lines should be replaced by:

if (is_convertible<category, dual_seekable>::value) {

if (which == BOOST_IOS::in) {

setg(0, 0, 0);

} if (which == BOOST_IOS::out) {

setp(0, 0);

}

} else {

setg(0, 0, 0); setp(0, 0);

}