Wt

When running my app I get an exception. The code worked fine with 3.2.2 and hasn't been modified.

terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_S_construct null not valid

Relevant gdb output:

#0  0x00007ffff5facfa5 in raise () from /usr/lib/libc.so.6
#1  0x00007ffff5fae428 in abort () from /usr/lib/libc.so.6
#2  0x00007ffff688ee3d in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/libstdc++.so.6
#3  0x00007ffff688cf36 in ?? () from /usr/lib/libstdc++.so.6
#4  0x00007ffff688cf63 in std::terminate() () from /usr/lib/libstdc++.so.6
#5  0x00007ffff688d18e in __cxa_throw () from /usr/lib/libstdc++.so.6
#6  0x00007ffff68dfbfd in std::__throw_logic_error(char const*) () from /usr/lib/libstdc++.so.6
#7  0x00007ffff7a18589 in char* std::string::_S_construct<char const*>(char const*, char const*, std::allocator<char> const&, std::forward_iterator_tag) ()
   from /usr/lib/libwt.so.34
#8  0x00007ffff68ebec3 in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&) ()
   from /usr/lib/libstdc++.so.6
#9  0x00007ffff7a4e87f in Wt::WRasterImage::drawImage(Wt::WRectF const&, std::string const&, int, int, Wt::WRectF const&) () from /usr/lib/libwt.so.34
#10 0x00007ffff789e133 in Wt::WPainter::drawImage(Wt::WRectF const&, Wt::WPainter::Image const&, Wt::WRectF const&) () from /usr/lib/libwt.so.34
#11 0x00007ffff789e1f7 in Wt::WPainter::drawImage(Wt::WRectF const&, Wt::WPainter::Image const&) () from /usr/lib/libwt.so.34
#12 0x0000000000422480 in avatar::handleResponse (this=0x7fffc40e8c00, err=..., response=...) at /home/mine/git/bettercodes/yajp-web-frontend/avatar.cpp:45
#13 0x0000000000423d21 in operator() (a2=..., a1=..., p=<optimized out>, this=<optimized out>) at /usr/include/boost/bind/mem_fn_template.hpp:280
#14 operator()<boost::_mfi::mf2<void, avatar, boost::system::error_code, const Wt::Http::Message&>, boost::_bi::list6<boost::system::error_code&, Wt::Http::Message&, Wt::NoClass&, Wt::NoClass&, Wt::NoClass&, Wt::NoClass&> > (a=<synthetic pointer>, f=..., this=<optimized out>) at /usr/include/boost/bind/bind.hpp:392
#15 operator()<boost::system::error_code, Wt::Http::Message, Wt::NoClass, Wt::NoClass, Wt::NoClass, Wt::NoClass> (a6=<synthetic pointer>, a5=<synthetic pointer>, 
    a4=<synthetic pointer>, a3=<synthetic pointer>, a2=..., a1=..., this=<optimized out>) at /usr/include/boost/bind/bind_template.hpp:203

The line from my code mentioned in item #12 (/home/mine/git/bettercodes/yajp-web-frontend/avatar.cpp:45) is

p.drawImage(WRectF(0,0,50,50),WPainter::Image(avatarURL,150,150)) ;