Guard the local variable cleanup in nogil functions with 'with gil' sections with the GIL.

Closes https://github.com/cython/cython/issues/3590

Cython/Compiler/Nodes.py

@@ -2146,8 +2146,9 @@ class FuncDefNode(StatNode, BlockNode):
             if entry.type.is_pyobject:
                 if entry.is_arg and not entry.cf_is_reassigned:
                     continue
+                assure_gil('success')
             # FIXME ideally use entry.xdecref_cleanup but this currently isn't reliable
-            code.put_var_xdecref(entry, have_gil=not lenv.nogil)
+            code.put_var_xdecref(entry, have_gil=gil_owned['success'])
 
         # Decref any increfed args
         for entry in lenv.arg_entries:
@@ -2163,7 +2164,7 @@ class FuncDefNode(StatNode, BlockNode):
                     continue
 
             # FIXME use entry.xdecref_cleanup - del arg seems to be the problem
-            code.put_var_xdecref(entry, have_gil=not lenv.nogil)
+            code.put_var_xdecref(entry, have_gil=gil_owned['success'])
         if self.needs_closure:
             assure_gil('success')
             code.put_decref(Naming.cur_scope_cname, lenv.scope_class.type)

tests/run/with_gil.pyx

@@ -463,6 +463,21 @@ def test_nogil_try_finally_error_label():
         print e.args[0]
 
 
+def void_with_python_objects():
+    """
+    >>> void_with_python_objects()
+    """
+    with nogil:
+        _void_with_python_objects()
+
+
+cdef void _void_with_python_objects() nogil:
+    c = 123
+    with gil:
+        obj1 = [123]
+        obj2 = [456]
+
+
 cdef void test_timing_callback() with gil:
   pass