Increase default boost::coroutine stack size to 1 MB

This fixes a problem with stack corruption in graph_draw().

configure.ac

@@ -161,6 +161,7 @@ AX_BOOST_COROUTINE
 if test "$BOOST_COROUTINE_LIB" = ""; then
    AC_MSG_WARN([No usable boost::coroutine found! Some functionality will be disabled in the library.])
 fi
+AC_DEFINE([BOOST_COROUTINE_STACK_SIZE], 1000000, [Stack size in bytes])
 AX_BOOST_GRAPH
 if test "$BOOST_GRAPH_LIB" = ""; then
    AC_MSG_ERROR([No usable boost::graph found])

src/graph/coroutine.hh

@@ -37,6 +37,7 @@
              namespace coroutines = boost::coroutines;
          }
 #    endif
+
 #endif // HAVE_BOOST_COROUTINE
 
 #endif // COROUTINE_HH

src/graph/graph_python_interface.hh

@@ -90,7 +90,9 @@ class CoroGenerator
 public:
     template <class Dispatch>
     CoroGenerator(Dispatch& dispatch)
-        : _coro(std::make_shared<coro_t::pull_type>(dispatch)),
+        : _coro(std::make_shared<coro_t::pull_type>
+                (coroutines::fixedsize_stack(BOOST_COROUTINE_STACK_SIZE),
+                 dispatch)),
           _iter(begin(*_coro)), _end(end(*_coro)), _first(true) {}
     boost::python::object next()
     {