From 415599f5d0b94a9156d7c03c7209d5c42634e237 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Gr=C3=B6nholm?= <alex.gronholm@nextday.fi>
Date: Wed, 27 Dec 2023 14:36:57 +0200
Subject: [PATCH] Fixed exceptions raised from decoder object hook causing
 SystemError

Fixes #201.
---
 docs/versionhistory.rst |  5 ++++-
 source/decoder.c        | 11 ++++++-----
 tests/test_decoder.py   |  9 +++++++++
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/docs/versionhistory.rst b/docs/versionhistory.rst
index defb976c..65b38eca 100644
--- a/docs/versionhistory.rst
+++ b/docs/versionhistory.rst
@@ -7,7 +7,10 @@ This library adheres to `Semantic Versioning <http://semver.org/>`_.
 
 **UNRELEASED**
 
-- Fixed ``SystemError`` when decoding a ``Fractional`` with a bad number of arguments
+- Fixed ``SystemError`` in the C extension when decoding a ``Fractional`` with a bad
+  number of arguments
+- Fixed ``SystemError`` in the C extension when the decoder object hook raises an
+  exception
 - Fixed a segmentation fault when decoding invalid unicode data
 
 **5.5.1** (2023-11-02)
diff --git a/source/decoder.c b/source/decoder.c
index 1ba709e4..7b53c3f5 100644
--- a/source/decoder.c
+++ b/source/decoder.c
@@ -939,11 +939,12 @@ decode_map(CBORDecoderObject *self, uint8_t subtype)
     }
     if (ret && self->object_hook != Py_None) {
         map = PyObject_CallFunctionObjArgs(self->object_hook, self, ret, NULL);
-        if (map) {
-            set_shareable(self, map);
-            Py_DECREF(ret);
-            ret = map;
-        }
+        if (!map)
+            return NULL;
+
+        set_shareable(self, map);
+        Py_DECREF(ret);
+        ret = map;
     }
     return ret;
 }
diff --git a/tests/test_decoder.py b/tests/test_decoder.py
index 7ea86075..0fd79dae 100644
--- a/tests/test_decoder.py
+++ b/tests/test_decoder.py
@@ -690,6 +690,15 @@ def __init__(self, state):
     assert decoded.state == {"a": 3, "b": 5}
 
 
+def test_object_hook_exception(impl):
+    def object_hook(decoder, data):
+        raise RuntimeError("foo")
+
+    payload = unhexlify("A2616103616205")
+    with pytest.raises(RuntimeError, match="foo"):
+        impl.loads(payload, object_hook=object_hook)
+
+
 def test_load_from_file(impl, tmpdir):
     path = tmpdir.join("testdata.cbor")
     path.write_binary(b"\x82\x01\x0a")