Add an explicit (although unnecessary) "noexcept" marker to the "PyCapsule_Destructor" function type to document explicitly that it must not emit exceptions.

See https://github.com/scipy/scipy/issues/17234

2 files changed, 34 insertions, 1 deletions

diff --git a/Cython/Includes/cpython/pycapsule.pxd b/Cython/Includes/cpython/pycapsule.pxd
index c3d12c749..08062da85 100644
--- a/Cython/Includes/cpython/pycapsule.pxd
+++ b/Cython/Includes/cpython/pycapsule.pxd
@@ -13,7 +13,7 @@ cdef extern from "Python.h":
     # access C APIs defined in dynamically loaded modules.
 
 
-    ctypedef void (*PyCapsule_Destructor)(object o)
+    ctypedef void (*PyCapsule_Destructor)(object o) noexcept
     # The type of a destructor callback for a capsule.
     #
     # See PyCapsule_New() for the semantics of PyCapsule_Destructor
diff --git a/tests/run/pycapsule.pyx b/tests/run/pycapsule.pyx
new file mode 100644
index 000000000..3bba08d88
--- /dev/null
+++ b/tests/run/pycapsule.pyx
@@ -0,0 +1,33 @@
+# mode: run
+
+import gc
+from cpython cimport pycapsule
+
+cdef int value = 5
+cdef bint destructed = False
+
+cdef void destructor(object obj) noexcept:
+    # PyPy's GC does not guarantee immediate execution.
+    global destructed
+    destructed = True
+
+
+def was_destructed():
+    return destructed
+
+
+def test_capsule():
+    """
+    >>> test_capsule()
+    True
+    >>> _ = gc.collect()
+    >>> was_destructed()  # let's assume that gc.collect() is enough to assert this
+    True
+    """
+    capsule = pycapsule.PyCapsule_New(&value, b"simple value", &destructor)
+
+    assert pycapsule.PyCapsule_GetName(capsule) == b"simple value"
+    assert pycapsule.PyCapsule_GetPointer(capsule, b"simple value") is &value
+    assert pycapsule.PyCapsule_GetDestructor(capsule) is &destructor
+
+    return pycapsule.PyCapsule_IsValid(capsule, b"simple value")