bpo-31505: Fix an assertion failure in json, in case _json.make_encoder() received a bad encoder() argument. (#3643)

1 files changed, 21 insertions, 0 deletions

diff --git a/Lib/test/test_json/test_speedups.py b/Lib/test/test_json/test_speedups.py
index 56f1882..5dad692 100644
--- a/Lib/test/test_json/test_speedups.py
+++ b/Lib/test/test_json/test_speedups.py
@@ -36,6 +36,27 @@ class TestEncode(CTest):
             b"\xCD\x7D\x3D\x4E\x12\x4C\xF9\x79\xD7\x52\xBA\x82\xF2\x27\x4A\x7D\xA0\xCA\x75",
             None)
 
+    def test_bad_str_encoder(self):
+        # Issue #31505: There shouldn't be an assertion failure in case
+        # c_make_encoder() receives a bad encoder() argument.
+        def bad_encoder1(*args):
+            return None
+        enc = self.json.encoder.c_make_encoder(None, lambda obj: str(obj),
+                                               bad_encoder1, None, ': ', ', ',
+                                               False, False, False)
+        with self.assertRaises(TypeError):
+            enc('spam', 4)
+        with self.assertRaises(TypeError):
+            enc({'spam': 42}, 4)
+
+        def bad_encoder2(*args):
+            1/0
+        enc = self.json.encoder.c_make_encoder(None, lambda obj: str(obj),
+                                               bad_encoder2, None, ': ', ', ',
+                                               False, False, False)
+        with self.assertRaises(ZeroDivisionError):
+            enc('spam', 4)
+
     def test_bad_bool_args(self):
         def test(name):
             self.json.encoder.JSONEncoder(**{name: BadBool()}).encode({'a': 1})