id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
856	iostreams file_descriptor::write fails under Win32	nobody	Jonathan Turkanis	"{{{
in 1.33.1, file_descriptor::write(), append mode implemented as

#ifdef BOOST_IOSTREAMS_WINDOWS
    if (pimpl_->flags_ & impl::has_handle) {
        if (pimpl_->flags_ & impl::append) {
            ::SetFilePointer(pimpl_->handle_, 0, NULL, FILE_END);
            if (::GetLastError() != NO_ERROR)
                throw detail::bad_seek();


it is common mistake to call GetLastError() without checking function return value first. MSDN has special note for SetFilePointer():

""Note  If the function returns a value other than INVALID_SET_FILE_POINTER, the call to SetFilePointer has succeeded. You do not need to call GetLastError.""

So, file_descriptor::write() fails, if there is old uncleaned ""last"" error

Regards,

valeri.antonov@gmail.com

}}}"	Bugs	closed		iostreams	None	Problem	fixed