fix error handling for closure creation in cdef void functions

Cython/Compiler/Nodes.py

@@ -1829,7 +1829,17 @@ class FuncDefNode(StatNode, BlockNode):
                     code.put_release_ensured_gil()
 
             # FIXME: what if the error return value is a Python value?
-            code.putln("return %s;" % self.error_value())
+            err_val = self.error_value()
+            if err_val is None:
+                if not self.caller_will_check_exceptions():
+                    warning(self.entry.pos,
+                            "Unraisable exception in function '%s'." %
+                            self.entry.qualified_name, 0)
+                    code.put_unraisable(self.entry.qualified_name, lenv.nogil)
+                #if self.return_type.is_void:
+                code.putln("return;")
+            else:
+                code.putln("return %s;" % err_val)
             code.putln("}")
             code.put_gotref(Naming.cur_scope_cname)
             # Note that it is unsafe to decref the scope at this point.

tests/run/closure_inside_cdef_T554.pyx

@@ -9,6 +9,23 @@ def call_f(x):
     """
     return f(x)
 
+
 cdef f(x):                # def  here => works fine
-   def g(y): return y*x  # cdef here => compile error
-   return g(x)           # faults@ INCREF(.*cur_scope->.*v_x
+   def g(y): return y*x   # cdef here => compile error
+   return g(x)            # faults@ INCREF(.*cur_scope->.*v_x
+
+
+def closure_in_void():
+    """
+    >>> genex = closure_in_void()
+    >>> list(genex)
+    ['a', 'b', 'c']
+    """
+    l = []
+    add_gen(l)
+    return l[0]
+
+
+cdef void add_gen(l):
+    x = "abc"
+    l.append((c for c in x))