cannot use some templates inside "with nogil"

[robertwb]

If a C++ templated function has more than one template argument, it cannot be used inside a "with nogil:" block, at least in 0.21.1, the version in debian sid. I have attached a MWE:

cythonside1.pyx does not use nogil, compiles and runs fine.

cythonside2.pyx uses nogil, fails to compile with the following error:

Error compiling Cython file:
------------------------------------------------------------
...


def test():
  cdef int arg
  with nogil:
    fun[&arg)
      ^
------------------------------------------------------------

cythonside2.pyx:9:7: Constructing Python tuple not allowed without gil

* cside.cpp:

template<typename A, typename B> void fun(A *arg1, B *arg2) {
  printf("In fun\n");
}

template void fun(int *arg1, int *arg2);

* cside.cppcythonside1.pyx:

cdef extern from "cside.hpp" nogil:
  void fun[A,B](int,int](&arg,)(A *arg1, B *arg2)

def test():
  cdef int arg
  fun[&arg)

* cside.cppcythonside2.pyx:

cdef extern from "cside.hpp" nogil:
  void fun[A,B](int,int](&arg,)(A *arg1, B *arg2)

def test():
  cdef int arg
  with nogil:
    fun[int,int](&arg, &arg)

At 2015-04-27T19:07:27Z josedavid added attachment cythonbug.zip

Migrated from http://trac.cython.org/ticket/848