fix a couple of function overloading corner cases

pythongen.py

@@ -189,7 +189,9 @@ def visit_overloaded_func_def(self, o):
         rest_args = None
         if is_more:
             rest_args = self.make_unique('args', fixed_args)
-            self.string(', *{}'.format(rest_args))
+            if len(fixed_args) > 0:
+                self.string(', ')
+            self.string('*{}'.format(rest_args))
         self.string('):\n' + indent)
         n = 1
         for f in o.items:
@@ -262,7 +264,10 @@ def make_overload_check(self, f, fixed_args, rest_args):
                 a.append(self.make_argument_check(
                     self.argument_ref(i, fixed_args, rest_args), t))
             i += 1
-        return ' and '.join(a)
+        if len(a) > 0:
+            return ' and '.join(a)
+        else:
+            return 'True'
 
     def make_argument_count_check(self, f, num_fixed, rest_args):
         return 'len({}) == {}'.format(rest_args, f.min_args - num_fixed)

test/data/pythongen.test

@@ -456,3 +456,33 @@ class A:
 [out]
 class A:
     def f(self): pass
+
+[case testOverloadWithAnyType]
+class A: pass
+def f(A x): pass
+def f(x): pass
+[out]
+class A: pass
+def f(x):
+    def f1(x): pass
+    def f2(x): pass
+    if isinstance(x, A):
+        return f1(x)
+    elif True:
+        return f2(x)
+    else:
+        raise TypeError("Invalid argument types")
+
+[case testOverloadWithZeroArgs]
+def f(x): pass
+def f(): pass
+[out]
+def f(*args):
+    def f1(x): pass
+    def f2(): pass
+    if len(args) == 1:
+        return f1(args[0])
+    elif len(args) == 0:
+        return f2()
+    else:
+        raise TypeError("Invalid argument types")