[Cython] Cython-0.17 builtin type import bug

[Robert Byrnes]

If a builtin type that differs between Python 2 and 3 (e.g., unicode)
is imported, then malformed C code is emitted by Cython-0.17: there is
an extraneous, unbalanced #if.

Here's a small reproducer:

shell$ cat foo.pyx
cdef extern from "Python.h":
    ctypedef class __builtin__.unicode [object PyUnicodeObject]:
        pass

shell$ cython foo.pyx
warning: foo.pyx:2:4: unicode already a builtin Cython type

shell$ gcc -c -fPIC -I/usr/include/python2.6 foo.c
foo.c:5:1: error: unterminated #else
foo.c: In function 'initfoo':
foo.c:574: error: expected declaration or statement at end of input
foo.c:535: error: label '__pyx_L1_error' used but not defined

This works for Cython-0.16 and earlier.

I think this was broken by ...

https://github.com/cython/cython/commit/558f4ef1c48ce091fa15b9319eb0f92cd4758f09

This patch for ModuleNode.generate_type_import_call seems to fix it:

--- a/Cython/Compiler/ModuleNode.py
+++ b/Cython/Compiler/ModuleNode.py
@@ -2281,7 +2281,6 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             module_name = '__Pyx_BUILTIN_MODULE_NAME'
             if type.name in Code.non_portable_builtins_map:
                 condition, replacement = Code.non_portable_builtins_map[type.name]
-                code.putln("#if %s" % condition)
             if objstruct in Code.basicsize_builtins_map:
                 # Some builtin types have a tp_basicsize which differs from sizeof(...):
                 sizeof_objstruct = Code.basicsize_builtins_map[objstruct]

Thanks,

--
Bob