fix: Route __repr__ and get_undecorated_callback behavior with __call__.

This fixes two issues:
- The Route.get_undecorated_callback() method failed to detect objects with a `__call__` method as callable. It also did not follow `__wrapped__` if present. Both works now.
- The Route.__repr__ method would fail if the callable does not have a `__name__` which can happen with `__call__`-able objects.

fix: #1488

Author: defnull

bottle.py

@@ -573,18 +573,17 @@ def get_undecorated_callback(self):
         """ Return the callback. If the callback is a decorated function, try to
             recover the original function. """
         func = self.callback
-        func = getattr(func, '__func__' if py3k else 'im_func', func)
-        closure_attr = '__closure__' if py3k else 'func_closure'
-        while hasattr(func, closure_attr) and getattr(func, closure_attr):
-            attributes = getattr(func, closure_attr)
-            func = attributes[0].cell_contents
-
-            # in case of decorators with multiple arguments
-            if not isinstance(func, FunctionType):
-                # pick first FunctionType instance from multiple arguments
-                func = filter(lambda x: isinstance(x, FunctionType),
-                              map(lambda x: x.cell_contents, attributes))
-                func = list(func)[0]  # py3 support
+        while True:
+            if getattr(func, '__wrapped__', False):
+                func = func.__wrapped__
+            elif getattr(func, '__func__', False):
+                func = func.__func__
+            elif getattr(func, '__closure__', False):
+                cells_values = (cell.cell_contents for cell in func.__closure__)
+                isfunc = lambda x: isinstance(x, FunctionType) or hasattr(x, '__call__')
+                func = next(iter(filter(isfunc, cells_values)), func)
+            else:
+                break
         return func
 
     def get_callback_args(self):
@@ -603,7 +602,9 @@ def get_config(self, key, default=None):
 
     def __repr__(self):
         cb = self.get_undecorated_callback()
-        return '<%s %s -> %s:%s>' % (self.method, self.rule, cb.__module__, cb.__name__)
+        return '<%s %s -> %s:%s>' % (
+            self.method, self.rule, cb.__module__, getattr(cb, '__name__', '__call__')
+        )
 
 ###############################################################################
 # Application Object ###########################################################

test/test_route.py

@@ -65,3 +65,45 @@ def test_callback_inspection_newsig(self):
             eval(compile('def foo(a, *, b=5): pass', '<foo>', 'exec'), env, env)
             route = bottle.Route(bottle.Bottle(), None, None, env['foo'])
             self.assertEqual(set(route.get_callback_args()), set(['a', 'b']))
+
+    def test_unwrap_wrapped(self):
+        import functools
+        def func(): pass
+        @functools.wraps(func)
+        def wrapped():
+            return func()
+
+        route = bottle.Route(bottle.Bottle(), None, None, wrapped)
+        self.assertEqual(route.get_undecorated_callback(), func)
+
+    def test_unwrap_closure(self):
+        def func(): pass
+        wrapped = _null_decorator(func)
+        route = bottle.Route(bottle.Bottle(), None, None, wrapped)
+        self.assertEqual(route.get_undecorated_callback(), func)
+
+    def test_unwrap_callable(self):
+        class Foo:
+            def __call__(self): pass
+
+        func = Foo()
+        wrapped = _null_decorator(func)
+        route = bottle.Route(bottle.Bottle(), None, None, wrapped)
+        self.assertEqual(route.get_undecorated_callback(), func)
+        repr(route) # Raised cause cb has no '__name__'
+
+    def test_unwrap_method(self):
+        def func(self): pass
+
+        class Foo:
+            test = _null_decorator(func)
+
+        wrapped = Foo().test
+        route = bottle.Route(bottle.Bottle(), None, None, wrapped)
+        self.assertEqual(route.get_undecorated_callback(), func)
+
+
+def _null_decorator(func):
+    def wrapper():
+        return func()
+    return wrapper