From: Yury Selivanov <yselivanov@sprymix.com>
Date: Wed, 2 Mar 2016 16:07:47 +0000 (-0500)
Subject: inspect: Fix BoundArguments.apply_defaults to handle empty arguments
X-Git-Tag: v3.6.0a1~538^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f9e1f2bda930054eed3115e19e9f3f7bfc83c1b6;p=python

inspect: Fix BoundArguments.apply_defaults to handle empty arguments

Patch by Frederick Wagner (issue #26347)
---

diff --git a/Lib/inspect.py b/Lib/inspect.py
index b65bec7adf..e830eb64ca 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -2591,8 +2591,6 @@ class BoundArguments:
         empty dict.
         """
         arguments = self.arguments
-        if not arguments:
-            return
         new_arguments = []
         for name, param in self._signature.parameters.items():
             try:
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 69ddb514d6..671e05a7b5 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -3324,6 +3324,13 @@ class TestBoundArguments(unittest.TestCase):
         ba.apply_defaults()
         self.assertEqual(list(ba.arguments.items()), [])
 
+        # Make sure a no-args binding still acquires proper defaults.
+        def foo(a='spam'): pass
+        sig = inspect.signature(foo)
+        ba = sig.bind()
+        ba.apply_defaults()
+        self.assertEqual(list(ba.arguments.items()), [('a', 'spam')])
+
 
 class TestSignaturePrivateHelpers(unittest.TestCase):
     def test_signature_get_bound_param(self):